I am having a similar problem. I posted at the end of the Official guide, but am not getting any responses.
I did not realize that I had okayed the update to 10.6.4, but after the kernal panic, I apparently approved the update. So, since I have a dual boot system, SL & Win7, booting into recovery mode didn't work. I found I was able to boot into the system if I used my original thumb drive that created my Hackintosh 10v. From there I was able to go into terminal mode, and proceed under the directions for being able to run NBI 0.8.4 RC1. It appeared that everything started working, so I then decided to reboot 1 more time without the thumb drive inserted. Now, all I have is the Grey Apple screen with the spinning circle - not the colored pinwheel. It has been spinning for about an hour. Should I stop it with a forced off, then restart again or let it spin a bit longer?
Well, never mind. Apparently, somehow my whole installation got corrupted, and repair disk won't even work. Says to backup any files and wipe and reinstall. Well, since the drive won't mount, I cannot backup any files to an external drive, so I am back to square one on recreating my dual boot dell mini.
Oh well, the trials and tribulations of life with a Hackintosh. Back to the guides I go. Hopefully, I don't have to reinstall the Windows 7 side...