Mark will have to answer that one, as far as I know, once you are ECUTEK'd you are stuck with it. However I have heard of a trick involving an accessport that supposedly gets the ECU back into a state that you can flash it with open source. But that may be a trick to fix a bricked ECU. I dont know the particulars of it.
Mark flew back to Beverly yesterday and is likely still recovering from the 10 days of work/stress of the swap down here. Ill get him in here asap