valgrind --tool=addrcheck --num-callers=12 --leak-check=full --log-file=vg /opt/bin/dia

Addrcheck, a fine-grained address checker for x86-linux.
==2155== Copyright (C) 2002-2005, and GNU GPL'd, by Julian Seward et al.
==2155== Using valgrind-2.4.0, a program supervision framework for x86-linux.
==2155== Copyright (C) 2000-2005, and GNU GPL'd, by Julian Seward et al.
==2155== 
==2155== My PID = 2155, parent PID = 2154.  Prog and args are:
==2155==    /opt/bin/dia
==2155== For more details, rerun with: -v
==2155== 
==2155== Invalid write of size 4
==2155==    at 0x8069198: dia_layer_widget_connectable_toggled (layer_dialog.c:739)
==2155==    by 0x349DB287: g_cclosure_marshal_VOID__VOID (in /usr/lib/libgobject-2.0.so.0.800.4)
==2155==    by 0x349C9214: g_closure_invoke (in /usr/lib/libgobject-2.0.so.0.800.4)
==2155==    by 0x349DADA7: (within /usr/lib/libgobject-2.0.so.0.800.4)
==2155==    by 0x349D9E77: g_signal_emit_valist (in /usr/lib/libgobject-2.0.so.0.800.4)
==2155==    by 0x349DA105: g_signal_emit (in /usr/lib/libgobject-2.0.so.0.800.4)
==2155==    by 0x343E1244: gtk_toggle_button_toggled (in /usr/lib/libgtk-x11-2.0.so.0.800.6)
==2155==    by 0x343E1687: (within /usr/lib/libgtk-x11-2.0.so.0.800.6)
==2155==    by 0x349DB287: g_cclosure_marshal_VOID__VOID (in /usr/lib/libgobject-2.0.so.0.800.4)
==2155==    by 0x349C94E8: (within /usr/lib/libgobject-2.0.so.0.800.4)
==2155==    by 0x349C9214: g_closure_invoke (in /usr/lib/libgobject-2.0.so.0.800.4)
==2155==    by 0x349DA630: (within /usr/lib/libgobject-2.0.so.0.800.4)
==2155==  Address 0x34F3F8D4 is 8 bytes after a block of size 36 alloc'd
==2155==    at 0x34149E4A: calloc (vg_replace_malloc.c:176)
==2155==    by 0x34A2B64E: g_malloc0 (in /usr/lib/libglib-2.0.so.0.800.4)
==2155==    by 0x3496B436: (within /usr/lib/libpangoft2-1.0.so.0.1001.0)
==2155==    by 0x3496B4AC: (within /usr/lib/libpangoft2-1.0.so.0.1001.0)
==2155==    by 0x34994687: pango_font_get_glyph_extents (in /usr/lib/libpango-1.0.so.0.1001.0)
==2155==    by 0x34D5AD95: (within /usr/lib/pango/1.4.0/modules/pango-basic-fc.so)
==2155==    by 0x34D5AFF7: (within /usr/lib/pango/1.4.0/modules/pango-basic-fc.so)
==2155==    by 0x3499BA74: (within /usr/lib/libpango-1.0.so.0.1001.0)
==2155==    by 0x349AB5E9: pango_shape (in /usr/lib/libpango-1.0.so.0.1001.0)
==2155==    by 0x349A1168: (within /usr/lib/libpango-1.0.so.0.1001.0)
==2155==    by 0x349A16DE: (within /usr/lib/libpango-1.0.so.0.1001.0)
==2155==    by 0x349A180A: (within /usr/lib/libpango-1.0.so.0.1001.0)
==2155== 
==2155== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)