Well, me thinks that ITPS is CRAP !!! I dont even want to get into the hassle that little guy put me through.
It sounds like its not really shutting your PC down and cutting the power before you have a chance. So either it's not wired correctly to your MOBO, your BIOS is not configured correctly with the ACPI commands OR the ITPS is just not working like it's advertised.
I'm waiting for my carnetix 1260 to arrive (hopefully today) and I'm praying this will solve my power issues once and forall !!!