the original wasn't a custom HBOOT, it was a custom MTD.
To revert - download recovery from here http://forum.xda-developers.com/show....php?t=1039954
Then - boot into recovery and format data\cache\system then fastboot flash the recovery you downloaded from the above link. Go back to recovery and again format the data, cache & system.
Then fastboot flash the custom HBOOT image from the V1.1 of this ROM - once done go back into recovery and flash the ROM
You lose 2 MB with the HBoot, but it makes life a lot simpler. I've used custom MTD's for as long as I can remember but I couldn't release a Hboot without testing.... Now I don't see the point going back to custom MTD.
Just ensure the MD5 matches.