Dual Head Setup Under Linux

I spent a couple of hours yesterday trying to get a two-monitor setup working under Linux (Fedora Core).  Today I figured it out.  In the BIOS (of the ASUS P4P800 Deluxe), there is a setting that prohibits the assignment of an IRQ to a video card on the PCI bus.  Since almost everyone uses the AGP slot for their video card, the setting in on by default.  But if you put a second video card in, it has to go in a PCI slot.  The default setting prevents it from getting an IRQ assigned.  Turning off the setting enabled Linux to use the second video card.