Multiple Monitor Problem

We currently have a 4 screen application, and two video cards. 3 of screens are displaying a forward view and the 4th is displaying a semi-static control panel (does not update much).

The problem we get is we cannot get the v-sync to sync up across all of the monitors. If all the monitors are not synced we of course will get shear lines in 2 of the 3 forward displays for our application. (We are able to Sync to one of the displays). Does anyone know of a software (windows API) based solution for handling this problem.

We are trying to avoid having to use some hardware based solution like using Quadro Card with G-sync card.