This bug is to inform Gentoo world that there is currently a nasty bug (for me) in kernel 3.8, rendering it unusable without a patch. Despite this being a fairly common box, it seems I was the only one affected by that bug (again), but who knows... Thankfully, it was already resolved upstream, and I'm using the patched 3.8 build without any glitches, but it has yet to be committed to 3.9 before it can land in some 3.8 minor release.
*** Bug 458946 has been marked as a duplicate of this bug. ***
The panel fitter patch has gone into 3.8.1, 3.4.34 and 3.0.67