I second your issue, with some different settings. I have the same motherboard, but I have installed Zeph's Rev 2. I then did the Time Machine update, and boom, instant reboot on load. Replaced System.kext and mac_kernel with patched, and I got to your situation. The only thing I got new is that I deleted /var/db/.AppleSetupDone (booting with -s) and then I got to create a new account. However, I cannot see the menu, and when I load any application, the apple menu appears but won't let log out. also right menu items aren't there, except for spotlight... All programs work, except for some estrange things - like disabling auto-login, wich freezes up the window. Then I do the first reboot, and guess what - I'm stuck with the new account dancing between logging in, showing up the dock and logging out - over and over again...

One thing I did other than the update was to disable the gameport of the motherboard on the BIOS. but I've enabled them again with no avail...

I'd really like to know what's going on - I mean, I should now be able to back up all my data, and reinstall, but I want to know what caused this in the first place, so that I won't do it again unintentionally. Any clues out there?