Also, any distribution worth its salt will accept bugs for any package it ships and (especially for something as important as the kernel) report the bugs upstream. This may be a slow process, but it does mean that bugs introduced by distributor patches are more likely to be caught.
There is a PPA for Linus's kernel, it's great for this stuff - makes upstreamable bug reports really easy. (Also for discovering "hey, my proprietary wifi now has a free driver!")
