Running today's (5/2/08) current Rawhide. See attached full dmesg
Created attachment 304431 [details] Full dmesg
Please try to reproduce without VirtualBox loaded (even if it's not active), as it can cause issues messing with page tables.
Currently running without Vbox module, will report back.
Changing version to '9' as part of upcoming Fedora 9 GA. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
I have this same error, but mine looks like httpd.worker causes it. It also happens shortly after every reboot, and renders to server unusable.
Created attachment 306684 [details] Kernel panic caused by httpd.worker
*** This bug has been marked as a duplicate of 249093 ***