audio midi setup losing connections

I had a midi I/O interface from digidesign which kept loosing connections. A new midi interface would be created in the setup window, not connected to my midi gear and the old one, with the connections still in place, would become greyed out and inoperative. This was a real PITA. I decided to shell out for a new midi I/O from MOTU and guess what, the same is happening

Does anyone have the same experience and if so, any solutions?

Thanks, cheers, Bob.