Okay, do a search in the forum for the ITPS operation. What you are experiencing is native to the ITPS. In all but a few instances it will not survive cranking. Also, if you have 12V devices such as HDD, Cdroms on the 12V bus then it is possible that the computer will reboot as well if your battery is weak. If you have access to a multimeter, check the battery voltage to the ITPS with the car running and with just the ACC line on. I bet there is a noticeable difference. From your description, I don't see any problems with your ITPS. It should cut power after about 50sec. total. I am working on code to reprogram the ITPS for longer delays so PM me if you are interested and I'll post it to the forum and can reprogram your chip for you when I am done.