Comment 5 for bug 241206

Happens here too; also, an ATI. To be more specific (since for some reason this is marked 'incomplete' despite multiple confirmations of the existence of the bug):

(1) open gnome-screensaver-preferences; observe that previews for screensavers work fine
(2) set to (for example) 'regard the computer as idle after' [1 minute] and 'activate screensaver when computer is idle'
(3) close the dialog, wait one minute
(4) observe that the screen starts to fade, as if the screensaver is kicking in
(5) immediately after the screen fades to black, the screen goes back to full brightness and does not lock. EXPECTED BEHAVIOR: the screensaver turns on; if the option is selected, the screen is locked.

This absolutely should not be low importance:
(1) the software fails to fulfill its primary task (blank the screen)
(2) this is a security problem, as the screen doesn't lock.

Didn't happen with any previous Ubuntu release on this same exact hardware (which has had every Ubuntu release on it since... hrm, whatever B was?)