ok try doing an actual full wipe so data, dalvik cache, and cache as well as system, then flash the superwipe, then try and flash the rom.and are you getting the message in recovery? are you trying to flash the PC36IMG file? because that is done in hboot and not in recovery.
and on a side not for xda you should re-post the question in the EVO Q&A- xda developers. you will get more hits there as well. but i'm glad you came here.
thanks for the xda tip, i posted it there. this is so weird, maybe the recovery isnt reading the partitions correctly?
, do you think i should upgrade my hboot to 2.16? ive read that you cant downgrade