firefox-3.1 crashed with signal 5 in _XError()

[MoLE]

Binary package hint: firefox-3.1

Crashed on startup, running jaunty in a virtual box 2.1 VM

ProblemType: Crash
Architecture: i386
DistroRelease: Ubuntu 9.04
ExecutablePath: /usr/lib/firefox-3.1b3pre/firefox-3.1
Package: firefox-3.1 3.1~b3~hg20090205r23182+nobinonly-0ubuntu1
ProcCmdline: /usr/lib/firefox-3.1b3pre/firefox-3.1
ProcEnviron:
 LANG=en_AU.UTF-8
 SHELL=/bin/bash
Signal: 5
SourcePackage: firefox-3.1
StacktraceTop:
 ?? () from /usr/lib/libgdk-x11-2.0.so.0
 _XError () from /usr/lib/libX11.so.6
 _XReply () from /usr/lib/libX11.so.6
 XGetWindowProperty () from /usr/lib/libX11.so.6
 ?? () from /usr/lib/xulrunner-1.9.1b3pre/libxul.so
Title: firefox-3.1 crashed with signal 5 in _XError()
Uname: Linux 2.6.28-8-generic i686
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare