I've recently switched to Win XP; which I'm very happy with.
However, from time to time (it's irregular, and I can't reproduce it at will); the Zone alarm connection icon "shows through" AH. That's to say suddenly I can see the standard Zone alarm systray flashing icon down in the rh corner of my screen.
While I can see the icon; my FPS apear to drop. I say appear, because I suddenly get that jerky freeze frame effect distinctive of low FPS but in fact I think it's the display locking and releasing in time to the Zone alarm icon's blinking.
Athlon 1 gig
192 Mb ram
Sound blaster
Geforce2 MX
Win XP; and every thing is on Win XP native drivers.
ADSL connect.