Hey Pete,
I've had that exact same thing happen a few times with me as well(owned unit since Oct 28). However it has not happened in weeks... I wouldn't sweat it. More than likely the unit is probably reacting to the IR signal from the remote in a weird sort of way... Sorry that's not an exact answer but since it is so intermittent it's hard to say for sure what is causing it. At least you know your not alone with that little problem.
Later,
CJ
Brooklyn, NY