Let me/us know if you figure it out. sorry i disappeared, had to run away from work.
My guess was you left the PG05IMG.zip on your sd card, and when you booted into HBoot (volume down/power) (post #4) the bootloader read the PG05 file and re-rooted your phone back to the stock ruu.
I know how you feel, when I first rooted my TB Clockwork was eff'd up and wouldn't restore a backup, it sent me into a kernel bootloop with no way to escape. Had to take the sd card out and use my pc to put the pg file back onto the sd card.....bla bla bla. Scared the crap out of me, but it worked out.