MacBookPro causing WIFI to drop for all users

Hello, I'm really hoping someone can help me because this problem has become really irritating.

In our house we have a Wireless-G Broadband Router (Linksys WRT54G with firmware version v8.00.0) and the signal is typically strong. When my roommate (who just got a new macbook pro) uses the internet, the wireless will sometimes disconnect - probably around once every few hours. It will disconnect from all computers, even though we can see our network on the list with full signal strength, we are unable to join it. We have to then go and unplug the router for a few seconds and plug it back in to make it work properly.

Furthermore, when the wifi goes out, connecting via LAN still works through the router.

What could be the problem - when the macbookpro in question has been gone for a week, the internet works beautifully, so I'm confident that this computer is the problem.

Please help, and tell me what other info/diagnostics I need to provide!
Thanks so much.