software-center crashed with TypeError in _draw_action_bar_separator(): Gtk.Style.paint_shadow() argument 1 must be gtk.gdk.Window, not None

Binary package hint: software-center

software-center problem

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: software-center 3.1.24.1
ProcVersionSignature: Ubuntu 2.6.38-7.38-generic-pae 2.6.38
Uname: Linux 2.6.38-7-generic-pae i686
Architecture: i386
Date: Thu Mar 24 14:38:59 2011
EcryptfsInUse: Yes
ExecutablePath: /usr/share/software-center/software-center
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110319)
InterpreterPath: /usr/bin/python2.7
ProcCmdline: /usr/bin/python /usr/bin/software-center
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
PythonArgs: ['/usr/bin/software-center']
SourcePackage: software-center
Title: software-center crashed with TypeError in _draw_action_bar_separator(): Gtk.Style.paint_shadow() argument 1 must be gtk.gdk.Window, not None
Traceback:
 Traceback (most recent call last):
   File "/usr/share/software-center/softwarecenter/view/softwarepane.py", line 305, in _draw_action_bar_separator
     a.width, 1)
 TypeError: Gtk.Style.paint_shadow() argument 1 must be gtk.gdk.Window, not None
UpgradeStatus: Upgraded to natty on 2011-03-23 (1 days ago)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare