Steps to reproduce:
1. choose element from another sheet (eg flowchart)
2. put element on the diagram BUT DON'T DESELECT IT
3. press 'del' to delete the element ("i meant to place another one")


Stack trace:
*** glibc detected *** dia: free(): invalid pointer: 0x097d01d0 ***
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6[0xb724a7cd]
/lib/tls/i686/cmov/libc.so.6(cfree+0x90)[0xb724de30]
/usr/lib/libglib-2.0.so.0(g_free+0x31)[0xb7501131]
dia(diagram_unselect_object+0x2d)[0x805f52d]
dia(diagram_unselect_objects+0x77)[0x805f607]
dia[0x8066c3e]
dia(edit_delete_callback+0x42)[0x806d722]
/usr/lib/libgobject-2.0.so.0(g_cclosure_marshal_VOID__VOID+0x49)[0xb75799d9]
/usr/lib/libgobject-2.0.so.0(g_closure_invoke+0x12b)[0xb756c62b]
/usr/lib/libgobject-2.0.so.0[0xb757d103]
/usr/lib/libgobject-2.0.so.0(g_signal_emit_valist+0x8c7)[0xb757e627]
/usr/lib/libgobject-2.0.so.0(g_signal_emit+0x29)[0xb757e7e9]
/usr/lib/libgtk-x11-2.0.so.0(_gtk_action_emit_activate+0x55)[0xb79c69d5]
/usr/lib/libgtk-x11-2.0.so.0[0xb79c8da4]
/usr/lib/libgobject-2.0.so.0(g_closure_invoke+0x12b)[0xb756c62b]
/usr/lib/libgobject-2.0.so.0[0xb757d103]
/usr/lib/libgobject-2.0.so.0(g_signal_emit_valist+0x68f)[0xb757e3ef]
/usr/lib/libgobject-2.0.so.0(g_signal_emit+0x29)[0xb757e7e9]
/usr/lib/libgtk-x11-2.0.so.0(gtk_accel_group_activate+0xd9)[0xb79c2899]
/usr/lib/libgtk-x11-2.0.so.0(gtk_accel_groups_activate+0xfa)[0xb79c299a]
/usr/lib/libgtk-x11-2.0.so.0(gtk_window_activate_key+0xda)[0xb7bcfe5a]
/usr/lib/libgtk-x11-2.0.so.0[0xb7bcfedc]
/usr/lib/libgtk-x11-2.0.so.0(_gtk_marshal_BOOLEAN__BOXED+0x60)[0xb7aa86b0]
/usr/lib/libgobject-2.0.so.0[0xb756ae49]
/usr/lib/libgobject-2.0.so.0(g_closure_invoke+0x12b)[0xb756c62b]
/usr/lib/libgobject-2.0.so.0[0xb757d753]
/usr/lib/libgobject-2.0.so.0(g_signal_emit_valist+0x68f)[0xb757e3ef]
/usr/lib/libgobject-2.0.so.0(g_signal_emit+0x29)[0xb757e7e9]
/usr/lib/libgtk-x11-2.0.so.0[0xb7bbce18]
/usr/lib/libgtk-x11-2.0.so.0(gtk_propagate_event+0x1ba)[0xb7aa19fa]
/usr/lib/libgtk-x11-2.0.so.0(gtk_main_do_event+0x317)[0xb7aa2bc7]
/usr/lib/libgdk-x11-2.0.so.0[0xb792412a]
/usr/lib/libglib-2.0.so.0(g_main_context_dispatch+0x182)[0xb74f9df2]
/usr/lib/libglib-2.0.so.0[0xb74fcdcf]
/usr/lib/libglib-2.0.so.0(g_main_loop_run+0x1a9)[0xb74fd179]
/usr/lib/libgtk-x11-2.0.so.0(gtk_main+0xb4)[0xb7aa3044]
dia(main+0x3f)[0x809ff3f]
/lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xdc)[0xb71f8ebc]
dia[0x805ed11]
======= Memory map: ========
08048000-080b5000 r-xp 00000000 08:04 786901     /usr/bin/dia-gnome
080b5000-080b9000 rw-p 0006c000 08:04 786901     /usr/bin/dia-gnome
080b9000-09804000 rw-p 080b9000 00:00 0          [heap]
b3800000-b3821000 rw-p b3800000 00:00 0 
b3821000-b3900000 ---p b3821000 00:00 0 
b39a7000-b39b2000 r-xp 00000000 08:04 2714472    /lib/libgcc_s.so.1
b39b2000-b39b3000 rw-p 0000a000 08:04 2714472    /lib/libgcc_s.so.1
b39c4000-b39c6000 r--p 00000000 08:04 1162721    /usr/share/locale-langpack/en_AU/LC_MESSAGES/gtk+.mo
b39c6000-b4022000 r--p 00000000 08:04 1112125    /usr/share/icons/hicolor/icon-theme.cache
b4022000-b58cb000 r--p 00000000 08:04 1163969    /usr/share/icons/crystalsvg/icon-theme.cache
b58cb000-b5f72000 r--p 00000000 08:04 1114665    /usr/share/icons/gnome/icon-theme.cache
b5f72000-b61c7000 r--p 00000000 08:04 1114672    /usr/share/icons/Tango/icon-theme.cache
b61c7000-b61cd000 r-xp 00000000 08:04 999156     /usr/lib/gtk-2.0/2.10.0/loaders/libpixbufloader-xpm.so
b61cd000-b61ce000 rw-p 00005000 08:04 999156     /usr/lib/gtk-2.0/2.10.0/loaders/libpixbufloader-xpm.so
b61ce000-b61fb000 r-xp 00000000 08:04 1211367    /usr/lib/dia/libvdx_filter.so
b61fb000-b61fc000 rw-p 0002d000 08:04 1211367    /usr/lib/dia/libvdx_filter.so
b61fc000-b622f000 r-xp 00000000 08:04 786844     /usr/lib/libxslt.so.1.1.20
b622f000-b6230000 rw-p 00032000 08:04 786844     /usr/lib/libxslt.so.1.1.20
b6230000-b6236000 r--p 00000000 08:04 1162720    /usr/share/locale-langpack/en_AU/LC_MESSAGES/libgnomeui-2.0.mo
b6236000-b623d000 r-xp 00000000 08:04 1211365    /usr/lib/dia/libpgf_filter.so
b623d000-b623e000 rw-p 00006000 08:04 1211365    /usr/lib/dia/libpgf_filter.so
b623e000-b6240000 r-xp 00000000 08:04 1211363    /usr/lib/dia/libpixbuf_filter.so
b6240000-b6241000 rw-p 00001000 08:04 1211363    /usr/lib/dia/libpixbuf_filter.so
b6241000-b624b000 r-xp 00000000 08:Aborted


Other information: