There are several references that speak to this issue.  Some are:

Auerbach, KG, The Breastfeeding Process, Chapter 9, in Breastfeeding
and Human Lactation (The
Brown Bible)

DeCoopman, J and Nehring S:  Overactive milk ejection reflex.
Breastfeeding Management for
Health Care Professionals, Ann Arbor, MI:  Resources in Latation
Professionals. P 42-44, 1993

Andrujiak, F. LaRose  The effects of an overactive let-down reflex.
Lactation Consultant Series
Unit #13 Avery Publishing

Personnally, when I suspect this I like to use sage or cold cabbage
compresses.  There are a number
of remedies mentioned to assist in correction.