No. I don't know if you even have to return the heatsink for warranty claims. But I would use it once for temp comparisons so it looks used. Personally, I don't think spending $50 on an aftermarket heatsink is worth it. I use the big 120 or 140mm fans to remove heat around my cpu.
You're right on not worth it - AMD did a great job on their stock HSFs for the A64. Unless you're going to OC or want uber-quiet, the stock HSF is good.
Did you mount a 120mm on the stock hsf or are you talking about the case fans?
Just make sure you do a really good job of removing the TIM. If they spot some AS on one of the chips without a heat spreader, game over. AS has been known to cause shorts between the connects on xp chips. That was what started them getting fussy, in the first place.
AMD does not care which HSF you are using. Getting OEM or retail does not matter.
If you f-uped the CPU from installing a 3rd-party HSF then just claim ignorance like the rest of us. Ive popped so many AMD chips from OCing and always got a replacement from AMD.
I maybe just know how to talk to the reps but did anyone else got screw by AMD this way?
<i><font color=red>Only an overclocker can make a computer into a convectional oven.</i></font color=red>