Disconnecting the battery also solved a problem I had with the compass. After a gentle drop once, the compass went into Calibrate mode and refused to reset despite my riding figures of eight for ages. I disconnected the battery for a minute and when I re-connected, voila, working compass (think I posted that somewhere else on this forum a while back). I didn't try shorting the + and - terminals while I was disconnected - this sounds sensible and scary at the same time - however, it's akin to a computer (I'm a PC tech by trade), having disconnected the power lead from a PC, pressing the power button flushes the power from the capacitors which can cure some hardware ills on occasion.