wogs, my car does that too. I reckon it's the aac valve. I'm just waiting until the bloody thing is put back together, then i'll clean it.
Turn key when it's col, revs drop really low. Sometimes, almost down to 0, and it actuall stalls. IF I blip it, then it'll kick up to 1200 then idle normally.
Maybe give it a go and let me know what happens?