I posted this once before, but I'm trying again. My screensaver in XP stops coming on, for no apparent reason. I know that cordless mice sometimes cause this problem, but I'm not using one. I never have a problem getting it started again - just go into Desktop Properties and make some kind of change and click Apply. And it'll last for a few hours, coming on after a couple of minutes like it's supposed to. But then I'll do some work, leave the machine, and notice later that the screensaver never started up again. It seems to happen randomly, not after I close out of any particular application.