Task switching & icon refresh delays

[Clive]

This is driving me nuts. I have a Mesh Matrix A64 3.2Ghz, 512Mb Ram, 256Mb Geforce FX5600, and over the last 4-5 months I get horrendous delays when task switching (either using ALT+TAB or from the task bar). I've tried some of the tweaks recommended, but I cannot figure this out. I've noticed too that the desktop icons sometimes take ages to refresh when I return to the desktop. I thought it might be the video card, but can't figure out where/why. Also, although I tried installing SP2, and in spite of a registry fix from Mesh support (known problem, apparently), it just crashes whenever I try - so I abandoned the attempt. Most recently, I've started getting (occasionally) a 1 - 2 minute delay coming out of the screensaver. Help please, before I put this thing through the window....!

Thanks
Clive