Poor video streaming over WRT54GS

[beatle]

My HTPC has a Linksys WMP54GS PCI NIC in it and it connects to my network via a Linksys WRT54GS w/the latest Sveasoft firmware. I'm using 128-bit WEP, FWIW. I cannot stream video smoothly over the network with this connection. I also have a Cisco Aironet 340 access point that hangs off the Linksys switch. When I connect to that network (also using 128-bit WEP) I have no problems. The signal strength is "low" on both, but streaming is smooth on the Cisco. I'd prefer to use the Linksys connection as I can get more throughput when copying files to the box, but it's not acceptable for watching videos. Are there any settings I should look for on the Linksys switch or NIC that would improve the smoothness?