ok, I figured it out, but instead of editing, I left the problem up there in case anyone has a similar problem.
I have the Ipac mounted fairly close to the P1 start button, the button nut (what ever you call it) was pressing against the USB plug in cord which was in turn pushing the NO prong of the cherry switch against the NC prong, resulting in an constant push loop.
I've shifted stuff around as best as I could, and it all seems fine now.
Now I can play Ultimate MK3 on my MKII machine, my XBOX 360 and my mame cab =)