Dell Latitude E6500 Wireless Card problems

The laptop has an Intel 5100 AGN wireless card and is running XP, the wireless router is a Linksys W610N.  The problem I have is the computer will not connect to the network unless I am sitting next to the wireless router.  When I am upstairs it sees the network, shows it a 4 bars but will not connect.  My xbox and satelitte reciever are both connected wirelessly from the same room.  My dell desktop on the floor above the living room is connected wirelessly as well.  My daughter, who is sitting next to me , her apple is connected. 

Windows wireless connections window will pop up, show my home network, I click on it, it asks for the network password, i type it in, a window pops up saying it is connecting to the network, then nothing.  Yet if I walk downstairs and sit on the couch next to the router, it has no problem connecting.

What could be wrong?