The Radeon 9600xt is a 1,5v card, not a 3,3v! I can only emphasize what Shimano said: Never try to give 3,3v to it!
For new cards such as the Radeon 9600xt (of the types AGP 8x or AGP 4x) 1,5v is the standard. 3,3v is, in fact, the *older* standard, which was used by AGP 2x or 1x cards and which is not supported by modern motherboards anymore (therefore, *if* you really had a card that needed 3,3v, buying a newer motherboard wouldn't be of any use. You'd rather need an older one, then ).
For those who are having problems with Smart Doctor warnings: check if your card is really getting the 1,5v it needs. Take a look at what Smart Doctor shows as 'Vcore' -- should be 1,5.
It may be that the card is getting to less because of power supply problems (I'm having the same -- my Radeon 9600xt, according to Smart Doctor, only gets 1,28v instead of the required 1,5v since my 300 watt PS is too weak -- ordered a better one yesterday... 8)). Again: 1,5v is all it needs. Nothing less, and nothing more!!!
If you don't trust Smart Doctor, I guess there are other tools to find out if your card (or any of your other pc components) is getting enough voltage, too (a google search will probably do). A nother hint for power supply problems is the PS getting hot or smelling bad (mine did both)... or smoking, but it'll probably be too late then ;-)
The minimum PS for a system that's running with a Radeon 9600xt is 350 watt - but depending on what other components you have, it might very well be more. However, TPJ2988, a 500 watt PS should really be enough... normally. But maybe it isn't working properly? x)
