I have the same problem. I do a restart and I get a sleeping monitor on restart. Sometimes other components don't seem to be starting properly either. My intellimouse sometimes fails to light (along with the sleepy monitor).
Asus motherboard - KT266 chipset (not 266A unfortunately)
GF3 Ti500 video
SB Live!
I'm running the latest drivers: detonators, 4in1's, sound.
Haven't flashed anything in a while though. Probably should do that, but I think I'm just gonna build a new box next week anyway. I'm itching for a 333 mobo and an R300. (and a new black lian-li aluminum case with the nifty plexiglass side)
The workaround: Do a shutdown, then hit the power button to start again. Restarts just don't seem to work.
If you find a true fix PLEASE post it. I've seen other threads on this topic elsewhere and no real fix.