Linsys WRT54GX, connection keeps dropping

Hello, I've been having a frustrating problem recently with this relatively old router. I got it right right around the time Pre-N was getting big. Anyway, I have AT&T DSL > SpeedStream DSL modem > Linksys WRT54GX. We have 4 desktops and 3 laptops using the connection. 3 Vista, 3 XP, 1 OSX/Win 7.

The connection to the router just randomly dies all the time. Sometimes it reconnects but the internet connection is rarely re-established. The modem has 5 lights on it, Power, Ethernet, DSL, Internet and Activity. When the connection dies, the internet light obviously goes off. The only way we can get the internet up and working again is to directly plug a computer into the modem, bypassing the router, and cycle the modem. Then open up firefox or whatever to kickstart the connection.

I cant figure out if the router is causing the connection to drop, the modem is causing it or maybe its just getting overloaded with all the different computer OS's or using multiple G vs N cards from different manufacturers.

Anybody run into a similar problem? Maybe I just need to get a new router.