A/C on.
Did the ECU reset. Seemed to work for one start and then it just stalls on subsequent starts. Tried to do the throttle pos reset and idle air reset and they seemed to do their thing, but still when you start it, the idle blips, and when it drops, it drops too far. If you catch it on the way down and tap the throttle it stops dropping and contiues to run as normal.
Its weird. I think it might be an air leak somewhere, or god forbit a knackered MAF. I think if it was the MAF though, it would do it all the time and not just when it was warm. Might put my stock airbox on at the weekend and see if it still does it