On thing I have found in the past is that some devices don't show in the device manager at all until the proper chipset drivers are loaded for the motherboard. If it were my system, and two different devices weren't showing in the same type of slot, I'd be inclined to perform a new installation of Windows into a different directory, preferably on another drive if at all possible, and then install the chipset drivers for the motherboard onto the newly installed installation, then see if the card shows up.
If yes, then it's a most likely that that the orginal Windows installation has some sort of corruption.
If no, it's probably some sort of hardware issue, requiring a new motherboard.
just my 2 centavos.
<S>
