I had the same problem. And my chiropractor told me to get ergo grips. I found a pair at MEC:
http://www.mec.ca/AST/ShopMEC/Cycling/BikeParts/HandlebarGrip/PRD~5019-800/mec-ergo-slip-on-grip-womens.jsp
First I didn't like them and my wrists were still hurting after a few rides. I thought about putting the old grips back but didn't do it right away. After using those ergo grips for about a couple of months my wrist pain went away completely. I have been riding all summer and my wrists never bother me again. Those grips are inexpensive; worth a try.