Most likely the driver board needs the Caps and BRs replaced - more like a "preventative maintenance".. See my Addams Resto thread for more info

Could also be the fact that it is REALLY hot and if the machine is on the same circuit as air con etc - it may trigger a reset.

I think you were correct. No problem todayafter getting in from work and no aircond going. Had a game without problems, but will keep an eye out for any further resets. Thanks guys