Created attachment 630772 [details] kernel oops message 3.6.2-2.fc17.x86_64 kernel is OK.
Can you recreate without all the vbox modules loaded?
It also happens on 3.6.2-2.fc17.x86_64 kernel. I never saw it on kernel-3.5.6-1.fc17.x86_64. It only happens under heavy load, I will try again without vbox modules.
This may be a dup of https://bugzilla.redhat.com/show_bug.cgi?id=820321 I will try its workaround.
*** This bug has been marked as a duplicate of bug 820321 ***