diff --git a/libisoburn/trunk/src/isoburn.c b/libisoburn/trunk/src/isoburn.c
index 10b8e065..dd9ffd33 100644
--- a/libisoburn/trunk/src/isoburn.c
+++ b/libisoburn/trunk/src/isoburn.c
@@ -48,7 +48,6 @@ int isoburn_new(struct isoburn **objpt, int flag)
  o->emulation_mode= 0;
  o->min_start_byte= 0;
  o->nwa= 0;
- o->treatment= 1;
  o->src= NULL;
  o->fabricated_disc_status= BURN_DISC_UNREADY;
  for(i=0;i<65536;i++)
@@ -233,7 +232,9 @@ int isoburn_find_by_drive(struct isoburn **pt, struct burn_drive *d, int flag)
  return(0);
 }
 
-int isoburn_prepare_disc(struct burn_drive *d, struct burn_disc **disc)
+static
+int isoburn_prepare_disc_aux(struct burn_drive *d, struct burn_disc **disc, 
+                             int new_img)
 {
  struct burn_source *wsrc;
  struct burn_session *session;
@@ -272,9 +273,9 @@ int isoburn_prepare_disc(struct burn_drive *d, struct burn_disc **disc)
  wopts.input_charset = NULL;
  wopts.ouput_charset = NULL;
  
- wopts.ms_block = o->nwa;
+ wopts.ms_block = (new_img ? 0 : o->nwa);
  wopts.src = o->src;
- wopts.overwrite = o->target_iso_head;
+ wopts.overwrite = (new_img ? NULL : o->target_iso_head);
  wsrc = iso_source_new_ecma119(o->target_volset, &wopts);
 
  track = burn_track_create();
@@ -283,3 +284,13 @@ int isoburn_prepare_disc(struct burn_drive *d, struct burn_disc **disc)
  
  return 1;
 }
+
+int isoburn_prepare_disc(struct burn_drive *d, struct burn_disc **disc)
+{
+	return isoburn_prepare_disc_aux(d, disc, 0);
+}
+
+int isoburn_prepare_new_image(struct burn_drive *d, struct burn_disc **disc)
+{
+	return isoburn_prepare_disc_aux(d, disc, 1);
+}
diff --git a/libisoburn/trunk/src/isoburn.h b/libisoburn/trunk/src/isoburn.h
index e29a8119..c1189924 100644
--- a/libisoburn/trunk/src/isoburn.h
+++ b/libisoburn/trunk/src/isoburn.h
@@ -47,9 +47,6 @@ struct isoburn {
  enum burn_disc_status fabricated_disc_status;
 
  /* --- Vreixo's part --- */
-
- /* Expansion treatment strategy: 1= grow, 2= modify, (any use for 0 ?) */
- int treatment;
  
  /* The data source for reading the old image */
  struct data_source *src;
diff --git a/libisoburn/trunk/src/libisoburn.h b/libisoburn/trunk/src/libisoburn.h
index 0dc848ae..9e2291f3 100644
--- a/libisoburn/trunk/src/libisoburn.h
+++ b/libisoburn/trunk/src/libisoburn.h
@@ -148,8 +148,22 @@ int isoburn_disc_track_lba_nwa(struct burn_drive *d, struct burn_write_opts *o,
     @param disc A burn_disc suitable to pass to isoburn_disc_write.
     @return <=0 error , 1 = success
 */
+// TODO we need to pass reduced ecma119_source_opts
 int isoburn_prepare_disc(struct burn_drive *d, struct burn_disc **disc);
 
+
+/** Prepare a disc for creating a new image from the contents of a previous
+    image volset plus the changes made by user. The generated burn_disc is
+    suitable to be written to any libburn drive. You shouldn't use the same
+    drive you're using as source.
+    @param d The source drive, grabbed with isoburn_drive_scan_and_grab().
+    @param disc A burn_disc suitable to pass to burn_disc_write.
+    @return <=0 error , 1 = success
+*/
+// TODO we need to pass reduced ecma119_source_opts
+int isoburn_prepare_new_image(struct burn_drive *d, struct burn_disc **disc);
+
+
 /** Start writing of the new session.
     This call is asynchrounous. I.e. it returns quite soon and the progress has
     to be watched by a loop with call burn_drive_get_status() until
@@ -172,6 +186,7 @@ int isoburn_activate_session(struct burn_drive *drive);
     @param pacifier_func If not NULL: a function to produce appeasing messages.
                          See burn_abort_pacifier() in libburn.h for an example.
 */
+// TODO implement this
 int isoburn_perform_write(struct burn_write_opts *o,
                           int (*pacifier_func)(void *handle, int patience, 
                                                int elapsed));