well, i have a p.o.s. dell 4550 and a p.o.s. ati radeon 9550 (hmm...both 550's) and i have never had any problem.
of course i take good care of my p.o.s. computer as far as viruses, spyware, installations, etc.
so its not all of the ati radeons....
actually, i've never had any problem with my dell. i've had it for 4 years now and only reformatted once. stuck 2 different kinds of 512 ram sticks and a new video card in it. runs like a champ.
i did have lightning run in on my cable modem and ruin my onboard ethernet...(which started a masochistic romp through dell's phone support of horror....that's dell's biggest problem).