9.3 Sunroof

I have a 2006 9.3 Aero (Australian). Lately the sunroof has started a life of its own. Sometimes the switch won't move it (sometimes I hear a click). Sometimes it will let me get it to the rear lifted up setting but then when I press the switch forward to close it, it will close, then immediately re-open again. It might be like this for 20 mins (once a few days), then suddenly revert back to working normally. The Saab dealers have looked at it and connected their computer but say the onboard computer is not logging any abnormalities. Trouble is that when it is acting up, by the time I get to the dealer it is working again. Any ideas anybody? Pete