A friend of mine just bought a 9800 Pro when he heard that I got an FX5900... he wanted to "one up" me. So when he got it installed he put the Catalyst 3.8's on, and was going to run some benchmarks and watch his 9800 Pro "crush" my FX5900... and it might have, if he could run any 3D applications.
Now don't get me wrong... I'm not saying this is an ATI issue... it might be a crappy card, I don't know what manufacturer made it. Or he may not have uninstalled the Detonators from his Ti4600 properly before he put this in, although I'm pretty sure he did a clean install of Windows.
Yes I know, many of you never had a problem with your ATI cards. Great. But my friend just had a problem with his... my cousin had problems with his 9600 Pro (which he later returned for an FX5900). On the other hand... I've had 5 different nVidia cards, one from every family from the GeForce 2 on up to the GeForce FX. Never had to do more than stick the card in, turn on the computer, and let Windows install drivers for it.