To me it almost sounds like a hardware problem, the very fact that cycling the power takes care of it makes me think that a contact is not being fully made. Kinda like a switch that doesn't quite hit but makes enough contact to pass the juice resulting in a dim glow. But give it another flick and wallah let there be light!

I have no electrical knowledge other than working in the automotive industry where occasionally I do have to troubleshoot switches and lights. But I have learned to check for the obvious first because that is usually the problem, it's almost never some weird voodoo from a parallel universe.