Thats a good point about the dipstick Tony. I had seen another thread on MLR where someone's kept popping out. I've checked mine and its still fully wedged in.
I had considered faulty gauge, but it seems to work fine as the car is warming up, and for normal journeys at lower speeds. It only seems to go loopy at higher speeds when its fully warm, and then its calmed down.
Just out of interest, wht sort of damage can high oil pressures do :duh:
I would guess high pressures could possibly damage your seals (front/rear main bearing, and valve stem seals), this usually happens when the engine is overfilled, which may seem like a daft question Steve, but have you checked that your engine isn't overfilled?