Comment 8 for bug 758592

I have a quite similar problem here: whenever I must enter my password to change some system settings (e.g. in kpackagekit), the password dialog appears only for the blink of an eye and is immediately replaced by an info box saying "Failed to obtain authentication".

When starting kpackagekit from the command line, the following is printed:

Application asked to unregister timer 0x38000002 which is not registered in this thread. Fix application.

I'm running Kubuntu 11.04, new install (no dist-upgrade). And it used to be working, this bug appeared about a week ago on my box.