Low idle after starter replacement?

Had a new starter put in ('99 New Jetta, 112k miles) and the 'cold idle' is much lower than before, around 500rpm. Once car is warmed up the idle is normal but it was not like this prior to getting the starter. Is there anything during that process that would cause this idling issue?? Thanks.

your starter might have been drawing a load from the battery causing idles to increase to charge battery more.