Multi-graphic card support under Vista (or lack of)

I've been trying to get my ATI x1900 PCI-express adapter to work in the second PCIe slot along with my nVidia 8800 GT PCI-express card. Vista keeps disabling the ATI (secondary PCIe slot) and notes that an incompatible video card has been disabled. According to this article at Microsoft, it explains that WDDM drivers under Vista now require "homogonous" video card support due to the new simplified VGA stack. Basically, meaning regardless of if you have it in a PCI slot or anything else, all graphics adapters MUST RUN under the same display driver. Right down to it sounds like the exact same model (not sure about this, as it sounds like some of the unified driver settings from ATI and nVidia might work ok, as long as it can use the same driver). Anyway...that is a bummer. I might look into installing XPDM drivers, which sounds like it will make everything revert back to the more complex old XP vga driver stack..but that sort of sucks. I really don't need a complex, high end second card. I just want to use it to display auxillary display screens of the glass cockpit in FSX (I hope that even works).

Also, I got my two 15" TFT-LCD touch screens from Newegg tonight. WOW, is all I can say. These kick the crap out of the 8" lilliput touch display (funny, they can use the same vista driver for the touch display I found for the lilliput, though...good, because they didn't have any for vista on the install disk). Anyway, I went with the HyVision MV155 Megavision with a native 1024x768 display. Gotta run and try FSX with this new monitor. I now have 7 monitors on my desk I'm trying to play around with...sigh. I really need to move this into a dedicated cockpit...