I have the screensaver turned to 'Never' done by rightclicking the desktop and going through the display menus. So i can leave it on all day and the screensaver will not appear, whether no apps are running, or a safari and other things are running - it NEVER sleeps.

But, if i leave Logic running, after a while the screensaver turns on and when i move the mouse to get back to Logic, Logic crashes! Any ideas?