I had an I-PAC2 that was going nutso on occasion, come to find out I had connected a cherry switch on momentary open instead of momentary closed (so basically the button was pressed all the time), yet for some reason the problem was rather intermittent, just occasionally out of nowhere i would start getting random button presses, yet most times it would work fine.
While its probably a software issue, its worth verifying the connections on all of your switches, just to eliminate that as a possible culprit.