Screen not locked after inactivity when promt appears

[LinuxTester]

When Screen Lock is activated, the screen won't go blank (using virtual box) when an application asks for a user interference (promt). It is possible to make an input action, like clicking on an window button of the promting program, before password promt appears.

the bug only affects gnome 3 for all I can say, since I cannot reproduce it using gnome 2 (classic) or Unity

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: gnome-screensaver 3.2.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-12.19-generic 3.0.4
Uname: Linux 3.0.0-12-generic i686
ApportVersion: 1.23-0ubuntu2
Architecture: i386
Date: Fri Sep 30 18:33:29 2011
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Beta i386 (20110921.2)
SourcePackage: gnome-screensaver
Symptom: security
Title: Screen not locked after inactivity
UpgradeStatus: Upgraded to oneiric on 2011-09-26 (4 days ago)

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please answer these questions:

* Is this reproducible?
* If so, what specific steps should we take to recreate this bug?
* Could you take a screenshot showing the issue?

This will help us to find and resolve the problem.

[Launchpad Janitor (janitor)]

[Expired for gnome-screensaver (Ubuntu) because there has been no activity for 60 days.]