2003 320d lumpy idle on start up?

[stevesingo]

The GF's 320d (85000miles) has developed a lumpy idle on start up, more so when cold, but still there when warm. Once on the move evertything is fine and performance is unchanged. When you come to a stop and let it idle it is still there but only 10% of what is there upon start up.

Any idea from the collective?

Steve