gimp-2.6 crashed with SIGSEGV in g_object_get()

Binary package hint: gimp

After I had copied a screenshot to the clipboard with gnome-screenshot I started GIMP to paste it in. When I pressed file nothing happened, the system seemed to become unresponsive. I pressed Ctrl+N to try again and now Compiz made the empty centre window grey.
The whole systems didn't respond, even though I was able to move the mouse. I've had unresponsiveness problems before, and there the solution was to go to a tty and kill GNOME Do. After I had done this and returned to the graphical session both GNOME Do and GIMP were gone and Apport was asking me whether I wanted to report this bug. I did so.

I'm running Compiz, GIMP and GNOME Do from the official repositories on an up-to-date amd64 version of Ubuntu 9.04, Alpha 5 at the moment.

If there is any more information you need, please don't hesitate to ask for it.

ProblemType: Crash
Architecture: amd64
DistroRelease: Ubuntu 9.04
ExecutablePath: /usr/bin/gimp-2.6
NonfreeKernelModules: nvidia
Package: gimp 2.6.5-1ubuntu2
ProcCmdline: gimp-2.6
ProcEnviron:
 PATH=(custom, user)
 LANG=nl_NL.UTF-8
 SHELL=/bin/bash
Signal: 11
SourcePackage: gimp
StacktraceTop:
 g_object_get () from /usr/lib/libgobject-2.0.so.0
 ?? ()
 g_closure_invoke ()
 ?? () from /usr/lib/libgobject-2.0.so.0
 g_signal_emit_valist ()
Title: gimp-2.6 crashed with SIGSEGV in g_object_get()
Uname: Linux 2.6.28-8-generic x86_64
UserGroups: adm admin audio cdrom crontab dialout dip fax fuse kvm libvirtd lpadmin munin netdev plugdev sambashare scanner tape vde2-net video