This sounds a bit unusual. Have a 4 car MCE group. 2 from late 80's the other 2 after 2000, all tied to the M/R monitor from 80's. Needless to say. Monitor's shot, group software out of date. Anyway. Trying to use procomm plus communicate with the 2 newer cars, everything seems working, except every few seconds later, procomm plus screen jumped back to the MCE starting screen. Let say I pressed f3, computer showing hoistway, about 5 sec. later, display refreshed and back to original. Any help? Thanks.