I'm running Ubuntu 11.10 on a Toshiba A300-16l laptop, and have been experiencing various very strange problems recently after upgrading to the latest Ubuntu release.
The most obvious problem is that I can't install updates through "Update Manager": pressing "Install Updates" simply disables the controls for a moment, then re-enables them with no apparent effect. At this time I would have expected an administrator prompt, but nothing appears.
A similar problem is apparent when trying to install new regional settings through "Language Support": after several minutes of watching a spinning throbber, the a dialog appears informing me that the "Task cannot be monitored or controlled". Again, no administrator prompt.
Finally, where I used to be able to sleep & hibernate my machine, now I can only shutdown or reboot. Both options simply log me out to the welcome screen, and forcibly shutting down through
sudo shutdown now hangs on the Ubuntu shutdown screen.
The problems persist after rebooting. I'm open for any ideas!