Router update: I was finally able to set up the filtering last night by MAC addresses, and I also finally got the 128-bit WEP encryption working, with a little help. The problem turned out to be that the router wants ASCII values, but the wireless NICs wanted HEX values. Once I finally figured that out, it was a simple conversion, and then it worked fine. By the way, in case anyone is wondering, 40-bit and 64-bit WEP encryption are the same thing. I ended up trying 64-bit WEP encryption when I couldn't get the 128 to work, and then switched back to the higher level only after I got the whole ASCII/HEX thing figured out.

Now I've just got to figure out how to map the webcam port to the router (using PAT - Port Address Translation), and then the webcam will be back online. Sorry for the delays.