My guess would be the kernel, but the best place to find developers who
might be able to help you is likely to be the dri-devel@lists.sf.net
mailing list (you're probably one of the only people to use graphics on
ia64 though).
(I asked Dave Airlie on irc when you reported this, he didn't have an
idea why the sarea map would be busted)
Cheers,
Julien