Every day I lose sales because my gateway rejects some customers' CVV2s. When we're lucky enough to talk to the customer on the phone, the customer insists that the CVV2 is correct, and they are able to use it on other sites. Sure enough, when we manually run the charge using only AVS, the charge goes through -- and none have been fraudulent.
We use CVV2 because too many zip codes (especially for international orders) were being rejected.
Do you have the same problem? Or do you think that our gateway just has a lousy database?