Rear audio control keeps dying

I have a 2004 Suburban I bought new. It has the rear audio controls. Within a few months te original RA contrl stopped working. THe dealership replace it. That one died after about 9 months. Just had another replaced this last Thanksgiving. It died about one month ago.

Is anyone else having this problem? What could be causing this?

I have been OK, so far, because the units have been replaced under warranty. However, I don't want to have to start paying for these things when they go out every few months. The rear audio is one of the must have features we wanted in a vehicle to kepp the kids entertained and we find it essential on long trips.