When my Screen saver is due to start I just get a blank screen. I have recently installed Compiz, before the screen saver worked as normal. I don't get locked out or any major problem but I just see a blank screen rather than one of the pre-installed screen-savers.
(OP states issue resolved)
Problem seems to have gone away. Screensavers now start with the settings to 5mins (not less). I still get a blank screen if I set settings to 1 or 2 mins. – motoringeek Aug 23 '11 at 22:15