=== modified file 'src/bridge.c'
--- src/bridge.c	2009-12-25 18:44:55 +0000
+++ src/bridge.c	2010-06-03 20:28:00 +0000
@@ -409,7 +409,14 @@
 void
 b_toggle_breakpoint (void)
 {
-  gui_editor_toggle_mark (app->editor);
+  GtkTextMark *insert;
+  GtkTextIter *iter;
+
+  insert = gtk_text_buffer_get_insert (GTK_TEXT_BUFFER(app->editor->buffer));
+  gtk_text_buffer_get_iter_at_mark (GTK_TEXT_BUFFER(app->editor->buffer), iter, insert);
+  gint line_no = gtk_text_iter_get_line (iter);
+
+  gui_editor_toggle_mark (app->editor, line_no);
 }
 
 AsmSource *

=== modified file 'src/callbacks.c'
--- src/callbacks.c	2010-05-31 11:36:18 +0000
+++ src/callbacks.c	2010-06-03 20:31:01 +0000
@@ -628,3 +628,15 @@
   text[strlen (text)] = 'h';
   gtk_entry_set_text (GTK_ENTRY (entry), text);
 }
+void
+on_line_mark_activated (GtkSourceView *view,
+                        GtkTextIter *iter,
+                        GdkEventButton *event,
+                        gpointer editor)
+{
+	if (event->button == 1 && event->type == GDK_BUTTON_PRESS)
+	{
+		gint line_no = gtk_text_iter_get_line (iter);
+		gui_editor_toggle_mark((GUIEditor *)editor,line_no);
+	}
+}

=== modified file 'src/callbacks.h'
--- src/callbacks.h	2010-05-31 11:36:18 +0000
+++ src/callbacks.h	2010-06-03 20:25:40 +0000
@@ -21,6 +21,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <gtk/gtk.h>
+#include <gtksourceview/gtksourceview.h>
 
 
 gboolean
@@ -127,3 +128,4 @@
 
 G_MODULE_EXPORT void on_mem_list_start_changed (GtkEntry *entry, gpointer user_data);
 
+G_MODULE_EXPORT void on_line_mark_activated (GtkSourceView *view, GtkTextIter *iter, GdkEventButton *event, gpointer editor);

=== modified file 'src/gui-editor.c'
--- src/gui-editor.c	2009-12-29 11:57:46 +0000
+++ src/gui-editor.c	2010-06-03 21:00:05 +0000
@@ -19,6 +19,7 @@
 */
 
 #include "gui-editor.h"
+#include "callbacks.h"
 
 GUIEditor *
 gui_editor_new (void)
@@ -34,6 +35,10 @@
 
   self->widget = gtk_source_view_new_with_buffer (GTK_SOURCE_BUFFER(self->buffer));
 
+  g_signal_connect ((gpointer) self->widget, "line-mark-activated",
+                    G_CALLBACK (on_line_mark_activated),
+                    self);
+
   self->scroll = gtk_scrolled_window_new (NULL, NULL);
 
   gtk_container_add (GTK_CONTAINER (self->scroll), self->widget);
@@ -157,27 +162,21 @@
 }
 
 void
-gui_editor_toggle_mark (GUIEditor * self)
+gui_editor_toggle_mark (GUIEditor * self, gint line_no)
 {
   g_assert (self);
 
-  gint y_buf;
   GtkTextIter line_start, line_end;
-  GtkTextMark *insert;
   GSList *marker_list;
   GtkSourceMark *marker;
 
-  insert = gtk_text_buffer_get_insert (GTK_TEXT_BUFFER(self->buffer));
-  gtk_text_buffer_get_iter_at_mark (GTK_TEXT_BUFFER(self->buffer), &(self->iter), insert);
-  y_buf = gtk_text_iter_get_line(&(self->iter));
-
   /* get line bounds */
-  gtk_text_buffer_get_iter_at_line (GTK_TEXT_BUFFER (self->buffer), &line_start, y_buf);
+  gtk_text_buffer_get_iter_at_line (GTK_TEXT_BUFFER (self->buffer), &line_start, line_no);
   line_end = line_start;
   gtk_text_iter_forward_to_line_end (&line_end);
 
   /* get the breakpoint markers already in the line */
-  marker_list = gtk_source_buffer_get_source_marks_at_line (self->buffer, y_buf, MARKER_BREAKPOINT);
+  marker_list = gtk_source_buffer_get_source_marks_at_line (self->buffer, line_no, MARKER_BREAKPOINT);
 
   if (marker_list != NULL && g_slist_length(marker_list)!=0)
 	{
@@ -187,7 +186,7 @@
   else
 	{
 	  /* no marker found -> create one */
-	  marker = gtk_source_buffer_create_source_mark (self->buffer, NULL, MARKER_BREAKPOINT, &(self->iter));
+	  marker = gtk_source_buffer_create_source_mark (self->buffer, NULL, MARKER_BREAKPOINT, &(line_start));
 	}
   g_slist_free (marker_list);
 	
@@ -371,4 +370,3 @@
 
   return pixbuf;
 }
-

=== modified file 'src/gui-editor.h'
--- src/gui-editor.h	2009-12-22 18:49:35 +0000
+++ src/gui-editor.h	2010-06-03 20:25:40 +0000
@@ -80,7 +80,7 @@
 void gui_editor_set_mark (GUIEditor * self, guint line_no, gboolean set);
 void gui_editor_set_highlight (GUIEditor * self, guint line_no, gboolean set);
 
-void gui_editor_toggle_mark (GUIEditor * self);
+void gui_editor_toggle_mark (GUIEditor * self, gint line_no);
 
 void gui_editor_clear_all_highlights(GUIEditor *self);