Switched the video lead to the other VGA port but there is no change.
In device manager is there a yellow exclamation mark or red x next to the device, if you right click on the device what options does it list, Im thinking you may have a driver conflict.
I don't find Integrated Graphics listed in either Device Manager (including Hidden Devices) or BIOS (including sub-menus).
Suggesting the 8800 GTS is working albeit whilst using the system drivers, unless configured otherwise in the BIOS an installed pci-e video card will override the onboard video chip.
Is this http://h20000.www2.h...vOID=2098#11360
where you got your unified drivers?
I am not suggesting you sign up or purchase anything but you could try running something like this http://www.driverdetective.org/
just to see what driver it picks up and recommends for the 8800 GTS, write the details down, uninstall the dr/det and then search online for the driver yourself (free).
You could also consider uninstalling the drivers, removing the card and running the onboard video chip for a while then shutting down and refitting the 8800 GTS and see if it makes any difference using the found new hardware wizard.