Sorry it took me so long to reply with details, but here they are. Thanks for the help.
Here is how my network is set up. It is a dsl connection. The dsl is then hooked up to a router. The router serves as a switch/wireless router. My dad's desktop is hooked up to the router (hard wired), then a printer (hard wired), and an ethernet cable which runs upstairs to a gb switch, which has to desktops hooked to it. I can get on the internet fine with an ethernet cable and sometimes with the wireless card, but when my brother gets on the interent with his xp home laptop (wireless) the airport has a hard time connecting to the internet that way. It seems though if I get on the internet first through the airport card works fine, but if he gets on before me then I ususally can't get on the internet. Thanks for the help.
P.S. Another ethernet cable is hooked into the router that runs upstairs to a xbox 360. The router is a linksys.