I had and have the same problem. When I take a long time not playing enough voltage receives (or amperage. Electric I do not know).
Sounds like a great failure of a large company like Line 6. They should find the solution. Know if the U.E. USA no problems or voltage, but in Argentina, and even in small towns, is unfortunately likely to happen.
I love the combination of my POD X3 Live and my Variax 700 guitar, when it works I feel there is nothing better, but when it fails (and may be at the wrong time) I do not know if you break on the floor or sit and mourn.
The truth is that if I had known there was a possibility of failure like that would never have bought.
Sorry for drafting errors, I am using a translator