Win XP & FS2K2 Degradation?

I know there has been some posts regarding this observation, but when they were HOT Topics, I had a new P4A hot rod (in March) and I didn't pay those posts much attention.But now it seems the sim's performance has slipped some. Once the blue in the sky became a solid white overcast suddenly, scenery sections blink sometimes from a solid hue into fine detail, ATC calls my "Chautauqua" ERJ-145s "Cathay or recently "China Southern."What's up here? I haven't added any scenery files yet, but lots of new aircraft and texures. I use TTools alot.Is this normal? Anybody else see this?If so, should I uninstall then reinstall?Any key items, other than the traffic .bgl and aircraft folder, should I back-up?Thanks a bunch! Sorry if this topic has been resolved earlier.Rick