Begin: Everything's running great during use. Speed is fine. And Then: Put her to sleep for more than 20 mins, and when I reopen, she's slow and quick to go to the pinwheel. Specifically: Randomg points, lags between windows then comes back While typing, and when switching browser tabs: Lags and gives pinwheel at random points and random intervals, which lasts for between a microsecond and several seconds 50% of the time it lasts long enough to force me to reboot The other 50% it gradually comes around to normal (Clarification on time stuck on pinwheel: Experimented a few times with leaving for a while - usually 1 to 3 hours, and letting it spin away. Always, when I return, it has always gone back to normal but slow function, though I don't know exactly how long it took.) Environment: I tend to run the same apps with same size docs or dbases open (no graphics, games, etc.) No noticeable correlation with which apps, or how many are running Same with browser - nothing to do with which browser (FF, sometimes Chrome), number of windows or tabs, etc. Machine Specs: Model Name: MacBook Pro (mid-2009) Model Identifier: MacBookPro5,4 Processor Name: Intel Core 2 Duo Processor Speed: 2.53 GHz Number of Processors: 1 Total Number of Cores: 2 L2 Cache: 3 MB Memory: 4 GB Bus Speed: 1.07 GHz Boot ROM Version: MBP53.00AC.B03 SMC Version (system): 1.49f2 Most grateful for any help!