It's been a couple years since I messed with WEP since I live in an area where no one can reach the signeal but me at home.
don't you have to enter the WEP key on each client machine..
another alternative I used when I lived in an apartment, which imo is easier than WEP is.
configure the router so it only allows mac adresses from your machnes... the only machines that get ip's are the ones on the mac address list at the router.
*Q6600@3330mhz 1.35v - True120 | Abit IP35pro | 2x2GB Gskil | 2 x EVGA GTS 250- shader 1890 | Corsair HX520 | OCZ Vertex 60GB/Seagate 7200.11 500GB
*x4 810@3250mhz 1.32v - Xigmatek S1283 | MSI K9A2 CF-F 790X | 2x1GB Kingston HyperX | 2 x MSI GTS 250- shader 1890 | Antec EW 500
*Q6600@3330mhz 1.36v - Scythe Mugen | Gigabyte GA-P35-DS3L | 2x1GB Ballistx | XFX GTX 260 (192) shader 1512 | OCZ Stealth 500w