Still not fully understanding what you have connected to what, by what.

My AP is connected to my Rio Receiver (the Receiver is the only device on the wired side of the AP).

I have several machines on a separate wired network. One of the machines, a Win2k Pro box, has a PCI wireless card in it (as well as it's wired network card). The Win2k machine routes between the wireless and wired networks.

I know this setup is odd, but it was the cheapest way of doing it at the time as Ethernet-WiFi bridges were more expensive than APs at that time (they still are, but at least they are closer in price).

I also have a laptop with a wireless card.

Does the AP provide the wireless access for the other wireless nodes, or does the PCI-wireless card operate in Ad-Hoc mode to service the other wireless nodes?

The whole network runs in infrastructure mode.