gdmsetup (testing) crashes when selecting "Browse" in the "Standard greeter" tab. Glibc 2.3.5-6 (testing) sends the following message:

*** glibc detected *** gdmsetup: free(): invalid pointer: 0xb790ac20 ***

======= Backtrace: =========
/lib/tls/libc.so.6[0xb7187423]
/lib/tls/libc.so.6(__libc_free+0x84)[0xb7187e84]
/usr/lib/libglib-2.0.so.0(g_free+0x22)[0xb7339ff2]
/opt/gnome/lib/libgnomeui-2.so.0[0xb7f66573]
/usr/lib/libgobject-2.0.so.0(g_cclosure_marshal_VOID__VOID+0x4b)[0xb73af44b]
/usr/lib/libgobject-2.0.so.0(g_closure_invoke+0x139)[0xb73a2e69]
/usr/lib/libgobject-2.0.so.0[0xb73b2c8b]
/usr/lib/libgobject-2.0.so.0(g_signal_emit_valist+0x6c0)[0xb73b3e00]
/usr/lib/libgobject-2.0.so.0(g_signal_emit+0x29)[0xb73b4169]
/usr/lib/libgtk-x11-2.0.so.0(gtk_button_clicked+0x51)[0xb7682b31]
/usr/lib/libgtk-x11-2.0.so.0[0xb76fdd35]
/usr/lib/libgtk-x11-2.0.so.0[0xb7750f6f]
/usr/lib/libgobject-2.0.so.0(g_closure_invoke+0x139)[0xb73a2e69]
/usr/lib/libgobject-2.0.so.0[0xb73b2c8b]
/usr/lib/libgobject-2.0.so.0(g_signal_emit_valist+0x6c0)[0xb73b3e00]
/usr/lib/libgobject-2.0.so.0(g_signal_emit+0x29)[0xb73b4169]
/usr/lib/libgtk-x11-2.0.so.0(gtk_tree_view_row_activated+0x5f)[0xb782288f]
/usr/lib/libgtk-x11-2.0.so.0[0xb782e0e6]
/usr/lib/libgtk-x11-2.0.so.0[0xb774f8a0]
/usr/lib/libgobject-2.0.so.0[0xb73a27a9]
/usr/lib/libgobject-2.0.so.0(g_closure_invoke+0x139)[0xb73a2e69]
/usr/lib/libgobject-2.0.so.0[0xb73b2852]
/usr/lib/libgobject-2.0.so.0(g_signal_emit_valist+0x42e)[0xb73b3b6e]
/usr/lib/libgobject-2.0.so.0(g_signal_emit+0x29)[0xb73b4169]
/usr/lib/libgtk-x11-2.0.so.0[0xb7840324]
/usr/lib/libgtk-x11-2.0.so.0(gtk_propagate_event+0xc5)[0xb774dca5]
/usr/lib/libgtk-x11-2.0.so.0(gtk_main_do_event+0x3cf)[0xb774e19f]
/usr/lib/libgdk-x11-2.0.so.0[0xb74b0f0a]
/usr/lib/libglib-2.0.so.0(g_main_context_dispatch+0x1fc)[0xb7332e8c]
/usr/lib/libglib-2.0.so.0[0xb733626b]
/usr/lib/libglib-2.0.so.0(g_main_loop_run+0x1b7)[0xb7336587]
/usr/lib/libgtk-x11-2.0.so.0(gtk_main+0xc1)[0xb774d2b1]
gdmsetup(main+0x1f4)[0x8053c04]
/lib/tls/libc.so.6(__libc_start_main+0xc2)[0xb7137df2]
gdmsetup[0x804ddf1]
======= Memory map: ========
08048000-0805c000 r-xp 00000000 03:01 849545 /opt/gnome/bin/gdmsetup
0805c000-0805d000 rw-p 00013000 03:01 849545 /opt/gnome/bin/gdmsetup
0805d000-0830b000 rw-p 0805d000 00:00 0 [heap]
b6900000-b6921000 rw-p b6900000 00:00 0
b6921000-b6a00000 ---p b6921000 00:00 0
b6a44000-b6a4e000 r-xp 00000000 03:01 1128488 /usr/lib/libgcc_s.so.1
b6a4e000-b6a4f000 rw-p 00009000 03:01 1128488 /usr/lib/libgcc_s.so.1
b6a63000-b6d64000 rw-p b6a63000 00:00 0
b6d65000-b6dc5000 rw-s 00000000 00:08 3244050 /SYSV00000000 (deleted)
b6dc5000-b6df5000 rw-s 00000000 00:08 3211281 /SYSV00000000 (deleted)
b6df5000-b6e14000 r--p 00000000 03:01 65481 /usr/X11R6/lib/X11/fonts/TTF/tr ebucbd.ttf
b6e14000-b6e35000 rw-p b6e14000 00:00 0
b6e35000-b6e39000 r-xp 00000000 03:01 81631 /usr/lib/gtk-2.0/2.4.0/loaders/ libpixbufloader-png.so
b6e39000-b6e3a000 rw-p 00003000 03:01 81631 /usr/lib/gtk-2.0/2.4.0/loaders/ libpixbufloader-png.so
b6e3b000-b6e5a000 r--p 00000000 03:01 65480 /usr/X11R6/lib/X11/fonts/TTF/tr ebuc.ttf
b6e5a000-b6e5c000 r-xp 00000000 03:01 1208074 /usr/lib/pango/1.4.0/modules/pa ngo-basic-fc.so
b6e5c000-b6e5d000 rw-p 00001000 03:01 1208074 /usr/lib/pango/1.4.0/modules/pa ngo-basic-fc.so
b6e5d000-b6e70000 r-xp 00000000 03:01 81679 /usr/lib/gtk-2.0/2.4.0/engines/ libclearlooks.so
b6e70000-b6e71000 rw-p 00013000 03:01 81679 /usr/lib/gtk-2.0/2.4.0/engines/ libclearlooks.so
b6e71000-b6e77000 r-xp 00000000 03:01 848792 /opt/gnome/lib/libglade/2.0/lib gnome.so
b6e77000-b6e78000 rw-p 00006000 03:01 848792 /opt/gnome/lib/libglade/2.0/lib gnome.so
b6e78000-b6e7a000 r-xp 00000000 03:01 49380 /usr/X11R6/lib/X11/locale/lib/c ommon/xlcDef.so.2
b6e7a000-b6e7b000 rw-p 00001000 03:01 49380 /usr/X11R6/lib/X11/locale/lib/c ommon/xlcDef.so.2
b6e7b000-b6ea7000 r--p 00000000 03:01 230688 /usr/lib/locale/en_US/LC_CTYPE
b6ea7000-b6eb0000 r-xp 00000000 03:01 526112 /lib/tls/libnss_files-2.3.5.so
b6eb0000-b6eb2000 rw-p 00008000 03:01 526112 /lib/tls/libnss_files-2.3.5.so
b6eb2000-b6eb5000 rw-p b6eb2000 00:00 0
b6eb5000-b6ec7000 r-xp 00000000 03:01 526118 /lib/tls/libnsl-2.3.5.so
b6ec7000-b6ec9000 rw-p 00011000 03:01 526118 /lib/tls/libnsl-2.3.5.so
b6ec9000-b6ecb000 rw-p b6ec9000 00:00 0
b6ecb000-b6ee9000 r-xp 00000000 03:01 1131262 /usr/lib/libexpat.so.0.5.0
b6ee9000-b6eeb000 rw-p 0001d000 03:01 1131262 /usr/lib/libexpat.so.0.5.0
b6eeb000-b6f1d000 r-xp 00000000 03:01 1131492 /usr/lib/libpng12.so.0.1.2.8
b6f1d000-b6f1e000 rw-p 00032000 03:01 1131492 /usr/lib/libpng12.so.0.1.2.8
b6f1e000-b6f30000 r-xp 00000000 03:01 54785 /usr/X11R6/lib/libXft.so.2.1.7
b6f30000-b6f31000 rw-p 00011000 03:01 54785 /usr/X11R6/lib/libXft.so.2.1.7
b6f31000-b6f32000 rw-p b6f31000 00:00 0
b6f32000-b6f36000 r-xp 00000000 03:01 54818 /usr/X11R6/lib/libXfixes.so.3.0
b6f36000-b6f37000 rw-p 00003000 03:01 54818 /usr/X11R6/lib/libXfixes.so.3.0
b6f37000-b6f44000 r-xp 00000000 03:01 54669 /usr/X11R6/lib/libXext.so.6.4
b6f44000-b6f45000 rw-p 0000c000 03:01 54669 /usr/X11R6/lib/libXext.so.6.4