diff --git a/libisoburn/burn_wrap.c b/libisoburn/burn_wrap.c
index 4b2f0712..af81acad 100644
--- a/libisoburn/burn_wrap.c
+++ b/libisoburn/burn_wrap.c
@@ -255,7 +255,7 @@ int isoburn_drive_scan_and_grab(struct burn_drive_info *drive_infos[],
  if(conv_ret<=0) {
    sprintf(msg, "Unsuitable drive address: '%s'\n",adr);
    msg[BURN_MSGS_MESSAGE_LEN-1]= 0;
-   burn_msgs_submit(0, msg, 0, "SORRY", NULL);
+   burn_msgs_submit(0x00060000, msg, 0, "SORRY", NULL);
    ret= 0; goto ex;
  }
 
@@ -309,8 +309,11 @@ int isoburn_find_emulator(struct isoburn **pt,
  ret= isoburn_find_by_drive(pt, drive, 0);
  if(ret<=0)
    return(0);
- if((*pt)->emulation_mode==-1)
+ if((*pt)->emulation_mode==-1) {
+   burn_msgs_submit(0x00060000,
+                    "Unsuitable drive and media state", 0, "FAILURE", NULL);
    return(-1);
+ }
  if((*pt)->emulation_mode==0)
    return(0);
  return(1);
@@ -388,8 +391,11 @@ int isoburn_disc_get_msc1(struct burn_drive *d, int *start_lba)
 #endif
 
  if(isoburn_disc_get_status(d)!=BURN_DISC_APPENDABLE &&
-    isoburn_disc_get_status(d)!=BURN_DISC_FULL)
+    isoburn_disc_get_status(d)!=BURN_DISC_FULL) {
+   burn_msgs_submit(0x00060000,
+                    "Media contains no recognizable data", 0, "SORRY",NULL);
    return(0);
+ }
  ret= isoburn_find_emulator(&o, d, 0);
  if(ret<0)
    return(0);
@@ -454,7 +460,7 @@ void isoburn_disc_write(struct burn_write_opts *opts, struct burn_disc *disc)
  write_type= burn_write_opts_auto_write_type(opts, disc, reasons, 0);
  if (write_type == BURN_WRITE_NONE) {
     sprintf(msg, "Failed to find a suitable write mode:\n%s", reasons);
-    burn_msgs_submit(0, msg, 0, "SORRY", NULL);
+    burn_msgs_submit(0x00060000, msg, 0, "SORRY", NULL);
     if(o!=NULL)
       o->wrote_well= 0;
     /* To cause a negative reply with burn_drive_wrote_well() */
@@ -531,8 +537,12 @@ int isoburn_set_start_byte(struct isoburn *o, off_t value, int flag)
  ret= burn_disc_get_multi_caps(drive, BURN_WRITE_NONE, &caps, 0);
  if(ret<=0)
    goto ex;
- if(!caps->start_adr)
+ if(!caps->start_adr) {
+   burn_msgs_submit(0x00060000,
+                    "Cannot set start byte address with this type of media",
+                    0, "FAILURE", NULL);
    {ret= 0; goto ex;}
+ }
  o->min_start_byte= value;
  if(value % caps->start_alignment)
    value+= caps->start_alignment - (value % caps->start_alignment);
@@ -557,7 +567,7 @@ int isoburn_get_min_start_byte(struct burn_drive *d, off_t *start_byte,
  ret= isoburn_find_emulator(&o, d, 0);
  if(ret<0)
    return(-1);
- if(ret==0)
+ if(ret==0) 
    return(0);
  *start_byte= o->min_start_byte;
  if(o->min_start_byte<=0)
@@ -701,11 +711,13 @@ int isoburn_report_iso_error(int iso_error_code, char msg_text[], int os_errno,
  int error_code, iso_sev, min_sev, ret;
  char *sev_text_pt, *msg_text_pt= NULL;
 
-/* <<< delete as soon as replacement appears in libisofs */
+ error_code= 0x00050000;
+
+/* It would have been neat ...
 #define ISO_ERR_CODE(e)     (e & 0x0000FFFF)
-
-
  error_code= 0x00050000 | ISO_ERR_CODE(iso_error_code);
+*/
+
  if(iso_error_code<0)
    msg_text_pt= (char *) iso_error_to_msg(iso_error_code);
  if(msg_text_pt==NULL)
diff --git a/libisoburn/isoburn.c b/libisoburn/isoburn.c
index ed3a758b..5b5e4b15 100644
--- a/libisoburn/isoburn.c
+++ b/libisoburn/isoburn.c
@@ -58,8 +58,12 @@ int isoburn_new(struct isoburn **objpt, int flag)
  int i, ret;
 
  *objpt= o= (struct isoburn *) malloc(sizeof(struct isoburn));
- if(o==NULL)
+ if(o==NULL) {
+   burn_msgs_submit(0x00060000,
+                    "Cannot allocate memory for isoburn control object",
+                    0, "FATAL", NULL);
    return(-1);
+ }
 
  o->drive= NULL;
  o->emulation_mode= 0;
@@ -276,6 +280,7 @@ int isoburn_prepare_disc_aux(struct burn_drive *d, struct burn_disc **disc,
  if (state != BURN_DISC_BLANK && state != BURN_DISC_APPENDABLE
      && (state != BURN_DISC_FULL || ! new_img)) {
    /* unsuitable status */
+   burn_msgs_submit(0x00060000, "Unsuitable media state", 0, "FAILURE", NULL);
    {ret= -2; goto ex;}
  }
  
@@ -322,10 +327,15 @@ int isoburn_prepare_disc_aux(struct burn_drive *d, struct burn_disc **disc,
  } else {
    int lba, nwa;
    ret = isoburn_disc_track_lba_nwa(d, NULL, 0, &lba, &nwa);
-   if (ret != 1)
+   if (ret != 1) {
+     burn_msgs_submit(0x00060000, "Cannot determine next writeable address", 0,
+                      "FAILURE", NULL);
      {ret= -3; goto ex;}
+   }
    if (nwa == 0 && state == BURN_DISC_APPENDABLE) {
      /* invalid nwa */
+     burn_msgs_submit(0x00060000, "Encountered 0 as next writeable address", 0,
+                      "FAILURE", NULL);
      {ret= -4; goto ex;}
    }
    iso_write_opts_set_ms_block(wopts, nwa);
@@ -347,7 +357,7 @@ int isoburn_prepare_disc_aux(struct burn_drive *d, struct burn_disc **disc,
  o->fifo = burn_fifo_source_new(wsrc, 2048, fifo_chunks, 0);
  burn_source_free(wsrc);
  if (o->fifo == NULL) {
-   fprintf(stderr, "Cannot attach fifo\n");
+   burn_msgs_submit(0x00060000, "Cannot attach fifo", 0, "FATAL", NULL);
    {ret= -1; goto ex;}
  }
 #endif /* ! Libisoburn_no_fifO */
@@ -416,6 +426,7 @@ int isoburn_prepare_new_image(struct burn_drive *d, struct burn_disc **disc,
 
 /* API @since 0.1.0
    @param flag bit0= this is a regular end, not an abort
+                     give up source reference
 */
 int isoburn_cancel_prepared_write(struct burn_drive *d, int flag)
 {
@@ -432,6 +443,8 @@ int isoburn_cancel_prepared_write(struct burn_drive *d, int flag)
  if(o->iso_source->version<1)
    return(0);
  o->iso_source->cancel(o->iso_source);
+ burn_source_free(o->iso_source);
+ o->iso_source= NULL;
  return(1);
 }
 
@@ -482,8 +495,11 @@ int isoburn_ropt_new(struct isoburn_read_opts **new_o, int flag)
  struct isoburn_read_opts *o;
 
  o= (*new_o)= calloc(1, sizeof(struct isoburn_read_opts));
- if(o==NULL)
+ if(o==NULL) {
+   burn_msgs_submit(0x00060000, "Cannot allocate memory for read options",
+                    0, "FATAL", NULL);
    return(-1);
+ }
  o->norock= 0;
  o->nojoliet= 0;
  o->noiso1999= 1;
@@ -616,8 +632,12 @@ int isoburn_igopt_new(struct isoburn_imgen_opts **new_o, int flag)
  struct isoburn_imgen_opts *o;
 
  o= (*new_o)= calloc(1, sizeof(struct isoburn_imgen_opts));
- if(o==NULL)
+ if(o==NULL) {
+   burn_msgs_submit(0x00060000,
+                    "Cannot allocate memory for image generation options",
+                    0, "FATAL", NULL);
    return(-1);
+ }
  o->level= 2;
  o->rockridge= 1;
  o->joliet= 0;
diff --git a/libisoburn/isofs_wrap.c b/libisoburn/isofs_wrap.c
index 8d531ef2..3ae073ba 100644
--- a/libisoburn/isofs_wrap.c
+++ b/libisoburn/isofs_wrap.c
@@ -116,19 +116,15 @@ int isoburn_read_image(struct burn_drive *d,
  struct isoburn *o= NULL;
 
  if(read_opts==NULL) {
-
-   /* >>> program error */;
-
+   burn_msgs_submit(0x00060000,
+                    "Program error: isoburn_read_image: read_opts==NULL",
+                    0, "FATAL", NULL);
    return(-1);
  }
  if(d != NULL) {
    ret = isoburn_find_emulator(&o, d, 0);
-   if (ret < 0)
+   if (ret < 0 || o == NULL)
      return 0;
-  
-   if (o == NULL) {
-     return -1;
-   }
    status = isoburn_disc_get_status(d);
  }
  if (d == NULL || status == BURN_DISC_BLANK || read_opts->pretend_blank) {
@@ -139,8 +135,12 @@ int isoburn_read_image(struct burn_drive *d,
    
    if (d == NULL) {
      /* New empty image without relation to a drive */
-     if (image==NULL)
+     if (image==NULL) {
+       burn_msgs_submit(0x00060000,
+                        "Program error: isoburn_read_image: image==NULL",
+                    0, "FATAL", NULL);
        return -1;
+     }
      /* create a new image */
      ret = iso_image_new("ISOIMAGE", image);
      if (ret < 0) {
@@ -164,14 +164,16 @@ int isoburn_read_image(struct burn_drive *d,
  }
  
  if (status != BURN_DISC_APPENDABLE && status != BURN_DISC_FULL) {
-   /* incorrect disc status */
+   burn_msgs_submit(0x00060000,
+                    "Program error: isoburn_read_image: incorrect disc status",
+                    0, "FATAL", NULL);
    return -4;	
  }
  
  memset((char *) &ropts, 0, sizeof(ropts));
 
  ret = isoburn_disc_get_msc1(d, &int_num);
- if (ret < 0)
+ if (ret <= 0)
    return -2;
  ms_block= int_num;
 
@@ -233,13 +235,15 @@ int isoburn_attach_image(struct burn_drive *d, IsoImage *image)
  int ret;
  struct isoburn *o;
 
- if (image == NULL)
+ if (image == NULL) {
+   burn_msgs_submit(0x00060000,
+                    "Program error: isoburn_attach_image: image==NULL",
+                    0, "FATAL", NULL);
    return -1;
+ }
  ret = isoburn_find_emulator(&o, d, 0);
- if (ret < 0)
+ if (ret < 0 || o == NULL)
    return 0;
- if (o == NULL)
-   return -1;
  if(o->image != NULL)
    iso_image_unref(o->image);
  o->image = image;
@@ -284,8 +288,12 @@ int isoburn_start_emulation(struct isoburn *o, int flag)
  struct burn_drive *drive;
  struct ecma119_pri_vol_desc *pvm;
  
- if(o==NULL)
+ if(o==NULL) {
+   burn_msgs_submit(0x00060000,
+                    "Program error: isoburn_start_emulation: o==NULL",
+                    0, "FATAL", NULL);
    return -1;
+ }
 
  drive= o->drive;
 
diff --git a/libisoburn/libisoburn.h b/libisoburn/libisoburn.h
index 59eff8c5..8ea59d9a 100644
--- a/libisoburn/libisoburn.h
+++ b/libisoburn/libisoburn.h
@@ -697,7 +697,7 @@ int isoburn_prepare_new_image(struct burn_drive *in_drive,
                          preparation call.
     @param flag Bitfield, submit 0 for now.
                 bit0= -reserved for internal use-
-    @return     <=0 error , 1 = success
+    @return     <0 error, 0= no pending preparations detectable, 1 = canceled
 */
 int isoburn_cancel_prepared_write(struct burn_drive *input_drive, int flag);
 
diff --git a/xorriso/xorriso_timestamp.h b/xorriso/xorriso_timestamp.h
index 87a6fa15..2598013f 100644
--- a/xorriso/xorriso_timestamp.h
+++ b/xorriso/xorriso_timestamp.h
@@ -1 +1 @@
-#define Xorriso_timestamP "2008.02.04.154405"
+#define Xorriso_timestamP "2008.02.04.184038"
diff --git a/xorriso/xorrisoburn.c b/xorriso/xorrisoburn.c
index 2b944b98..dcf85780 100644
--- a/xorriso/xorrisoburn.c
+++ b/xorriso/xorrisoburn.c
@@ -298,10 +298,13 @@ int Xorriso_report_iso_error(struct XorrisO *xorriso,
  int error_code, iso_sev, min_sev, ret;
  char *sev_text_pt, *msg_text_pt= NULL;
 
-/* <<< delete as soon as replacement appears in libisofs */
-#define ISO_ERR_CODE(e)     (e & 0x0000FFFF)
+ error_code= 0x00050000;
 
+/* It would have been neat ...
+#define ISO_ERR_CODE(e)     (e & 0x0000FFFF)
  error_code= 0x00050000 | ISO_ERR_CODE(iso_error_code);
+*/
+
  if(flag&1)
    msg_text_pt= (char *) iso_error_to_msg(iso_error_code);
  if(msg_text_pt==NULL)
@@ -838,6 +841,10 @@ no_track:;
    Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "FATAL", 0);
    goto ex;
  }
+ /* Done early to free any reference to the libisofs resources via disc */
+ if(disc!=NULL)
+   burn_disc_free(disc);
+ disc= NULL;
  /* To wait for the end of the libisofs threads and their messages. */
  isoburn_sync_after_write(source_drive, 1);
  Xorriso_process_msg_queues(xorriso,0);
@@ -1565,12 +1572,15 @@ int Xorriso_process_msg_queues(struct XorrisO *xorriso, int flag)
      else {
        ret= burn_msgs_obtain("ALL", &error_code, xorriso->info_text, &os_errno,
                              severity);
-       tunneled= (error_code>=0x00050000 && error_code<0x00060000);
+       if(error_code>=0x00050000 && error_code<0x00060000)
+         tunneled= -1; /* "libisofs:" */
+       if(error_code>=0x00060000 && error_code<0x00070000)
+         tunneled= 1;  /* "libisoburn:" */
      }
      if(ret<=0)
    break;
      Xorriso_msgs_submit(xorriso, error_code, xorriso->info_text, os_errno, 
-                         severity, ((pass&&!tunneled)+1)<<2);
+                         severity, ((pass+tunneled)+1)<<2);
      count++;
    }
  }