Access point problems with WUSB54G v4

This problem has been driving me crazy. There's gotta be something obvious I'm missing.

I use a WRT54GS v7 in the basement of my house and the said adapter upstairs. I downloaded the latest driver (WUSB54Gv4_20051110.exe) from linksys' website since I had lost the software sometime back. When I attempt to connect with the computer with the wireless adapter, I can see my network (and a couple of my neighbors' networks for that matter), my signal strength usually ranges between 40-60%. But no matter how strong the signal, after entering my WEP key it still gives me the classic 'cannot associate with access point' error. It doesn't even seem like it tries to connect. When I try to connect with Windows Wireless Config, it shows the network as 5 green bars, yet cannot connect either.

I've spent a couple hours with the Indian Trade Co-- I mean Linksys tech support, and they think I have the wrong version of the driver I downloaded, although I'm pretty certain I don't. So they told me that they would e-mail me the correct driver and, well, that was a day ago. I guess that was just their way of saying "You're a lost cause, stop tying up our line. Thankyoucomeagain."

Any suggestions as to how to figure out what I'm doing wrong? Any help is appreciated. I like to think I know a little bit about computers, but I know next to nothing about networking...so if you could dumb down your responses as much as possible, I'd be grateful. =)