Idle temporarily rises when A/C starts??

[Fluellen]

I've had the following "problem" for quite a while now. When the car is at idle, and the A/C cuts in or I turn it on via the snowflake button, the idle rpm go up by perhaps 100-200 rpm for a second or so, and then it goes down to normal.

My recollection is that it didn't use to do that... that the operation (A/C clutch engaged or not) was very transparent, almost unnoticeable.

Is my recollection correct, and if so, what could be the issue here? 2001 986S. A/C works fine apart from this...

Thanks in advance!