I'm having the same problem. I idle high (not all the time) then it will shoot up to about 2500. I tap the gas, it goes down then right up again. I found that if I shut the car off completely and then started it again it would go back to normal. Its making me so crazy that I'm ready to send it in to BMW to have it checked out.
so what you're saying is that i let the car warm up, unplug the connector from the idle control valve, adjuat the setting then plug it back in should help this?
I'll give it a shot