Serious Reaper Issues!

Had Reaper working nicely for a while, no problems whatsoever except for occaisional crashes. Now.. all of a suddent it takes 2-3mins to load a project, crashes constantly, tells me theres CFD errors (not enough memory to load tracks), makes glitching sounds, the interface lags to high heaven and I can't render anything. As far as I know, I hadn't changed a single setting. Under CPU usage its at ~55%. I've closed down all background programs and its the same, I've rolled back to an older version and its the same. Any settings I can use inside reaper to minimize this memory usage or find the cause of the problem? Is there a way to revert to default settings? Perhaps this is an ASIO buffer/setting issue? Any help much appreciated.

what version of Reaper? OS? Ram? Are you experiencing similar problems with any other DAWs? Do the crashes occur even if you open with the plugins bypassed? greetings .t

- is your hard disk OK? That's what I was wondering, too. Also, check your memory sticks. Maybe one has jiggled loose. One last thing, what about available space on your project drive? If you're running low on space then all kinds of bad mojo can happen.