Asus P5B-VM DUAL-HEAD?

I have a system based on the Asus P5B-VM - a generally good mobo and I am quite happy with it. But, silly me lost sight of one of my initial requirements.

Dual monitor support.

Does anybody know what will happen if I add a PCI-Express card to the system - will I simply replace the existing graphics with the new one or will an additional card provide extra monitor support. In the long-term I would love to have 3 monitors so I'd rather not lose the on board if possible.

Perhaps you know what BUS the onboard graphics (G965 - X3000) lives..

From looking at the manual it doesn't seem that the onboard graphics would be disabled with another card (it doesn't specifically say this, but on the option for setting the primary graphics device in allows PEG/IGD as an option).

Maybe try a post in the general HEXUS.HardStuff, I'm sure there are enough people out there with a board like this to tell you.