Hmm, that's highly mysterious. Did you try removing the backup battery as well? If that doesn't help, then I'm pretty sure the problem is unrelated to HT, since otherwise it would be the first program to permanently brick a TI. Perhaps the binfiles are corrupted. Or are you by any chance trying to run the 83p version instead of 8xp?
In any case I'm still completely clueless as to what causes the bug. I'm therefore intending to rewrite HT from scratch. I've done some preliminary work already, but won't get around to really delve into it before January. So please be patient, and once again sorry for the troubles caused.