If you're talking about the ASPM regression introduced in 2.6.38, it looks like it's been resolved in a patch that should drop in 3.3.

Here's a Phoronix article on the issue and fix that covers it in detail: http://www.phoronix.com/scan.php?page=article&item=linux...

And here's (what I think is) the corresponding bug for Ubuntu: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/760131

Please note that even though that Ubuntu bug is marked as fixed, the following comment on it seems to call that into question: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/760131/...

Either way, it sounds like it will be fixed in 12.04.