DELL D630 - CANNOT CONNECT TO INTERNET

I have a Dell Latitude D630 which is part of my home Linksys wireless network (WRT54GL router) and Wireless-G Access point & DSL Cable - Router. My other two computers (Dell desktop and Gateway laptop) get to the internet fine BUT the Dell D630 - even when showing in the "wireless network connections" as 'connected' with a 'very good' signal and speed of 54Mbps will NOT connect to the internet. I get the "unable to display webpage" message when I click the Internet Explorer icon.

 

The Linksys router is set up with a secure 64-bit WEP encryption with SSID enabled. I don't know what other information to provide - perhaps someone (anyone) can advise what may be the problem? I've been on the phone with Dell, Verizon and Linksys and after pulling cables, changing settings and generally going crazy, I cannot get to the internet. Dell said "Go buy a new router." Please HELP!!