Connectivity issues w/ security enabled

Hi,

I have a Dell Inspiron 8500 and a Dell truemobile 2300 router. I am having
strange problems connecting over my wireless network at home.

1. If I disable security settings on the router then I can connect fine
provided the wireless connection is not part of the network bridge. The
moment I add it to the bridge w/ same settings (and NO security), it cannot
connect.

2. If I enable security on the router (either WEP or WPA) then I cannot
connnect no matter whether the wireless connection is part of the bridge or
not. I have made sure that the security settings in my wireless connection
match those onthe router (keys, protocol, alg etc.).
Just to see what is the issue I configured my other laptop IBM T40 with same
security settings as those on the router and it can connect fine. so the
appears with the wireless client on the dell laptop when security is enabled
but for the life of me I cant seem to figure out what could be wrong since I
have verified the security settings n times. Note as I mentioned with
security disabled and with the wireless connection removed from the network
bridge it can connect.

The dell laptop is running Win XP Pro SP2. Any help would be greatly
appreciated.

TIA
Jay