FOB Presence Issue?

My Volt has been very trouble free the entire time I've owned it, with only very minor items needing attention. I am beginning to see one of those minor items show up now with the occasional message saying the FOB isn't detected, or something to that effect. So far it hasn't been a problem, but of course, one can't move the car if the system decides it can't see the FOB. Will hope that should the system decide not to let me drive, I can call OnStar and get help! :-) Something to mention to the service writer next time I get the tires rotated.