update-manager window becomes unusable when invoked when the screen is locked

[Mister X]

When the update-manager window is brought up while the screen is locked, the user can't interact with it in any way. Can't switch to it, neither by alt-tabbing nor by using the applications panel. You have to close the window and restart the update-manager for it to work again.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: update-manager 1:0.156.14.5
ProcVersionSignature: Ubuntu 3.2.0-25.40-generic 3.2.18
Uname: Linux 3.2.0-25-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.0.1-0ubuntu8
Architecture: amd64
Date: Fri Jun 22 10:22:17 2012
GsettingsChanges:
 com.ubuntu.update-manager first-run false
 com.ubuntu.update-manager launch-time 1340353301
 com.ubuntu.update-manager show-details true
 com.ubuntu.update-manager window-height 693
 com.ubuntu.update-manager window-width 691
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta amd64 (20120301)
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
UpgradeStatus: No upgrade log present (probably fresh install)