I'd do a soft reset first. If you don't know how, read the manual or Google it. A soft reset helped this wkend on a unit I was helping a friend with. Another option is to switch the units to see if is power related, whether you think it is or not. I also have Gen 1 and after a while, it just seems to have strange things occur. A soft reset seems to fix things. I think over time, the internal memory gets loopy much like computers do.
LOVE GOLD Jimmy