OpenSUSE Wireless :: Exchanged Modem/router For Same Model But Now Cannot Connect To Internet Using WEP

I had an ATT "2Wire" modem/router that was working but connection to the Internet was often poor. An ATT technician came to my home and swapped out the modem/router for the identical model. I changed the ESSID and WEP code to match the new unit and everything was fine with the following wireless units: a wireless desktop, two cellphones, three wireless Archos tablets, and a couple of e-reader tablets. So all seemed to be fine wirelessly. However...

My laptop (SuSE 11.0, KDE3) simply won't connect no matter what I do. I changed the ESSID and WEP info in the lappy exactly as was done with the other wireless devices named above. But no good. The lappy does see the modem/router (a good, strong signal appears in KNetworkManager). But it seems as if the modem/router is rejecting the lappy's attempted handshake using the new ESSID and/or WEP information.

I thought that perhaps there was something wrong with the lappy's wireless card, so I took it to a Starbucks to see if it would connect there on an open network, and it did without problem. So the lappy's wireless card appears to be working fine. It just won't talk to the encrypted modem/router at home. Here are the settings on the lappy. Hopefully something here is easily identified as the culprit. With all the clicking I've done it certainly is possible that I ticked something that should not have been ticked and just don't realize what I've done.

Network settings screen:
Global options tab:
Network setup method: user controlled with Network Manager
Change default route via DHCP (ticked)

[code]....

Why won't the new modem/router which is exactly the same as the old one except for the ESSID and WEP work with my lappy yet it does work with a bunch of other wireless devices?