Networking & wireless: Linksys Router Problem

Linksys Router Problem

Hey all-

I was hoping someone could help me out with this problem:

My Linksys WRT54g router was originally set up between two desktop computers: one via ethernet (the computer on which the router was installed), and one via wifi. The computers shared a Verizon DSL connection, and there were no problems.

Now that I am away at college, the master computer is not connected via ethernet to the router. There were no problems initially.

We then purchased a new Dell E1505 laptop, and didn't know the security settings on the router, so we did several hard resets to enable the Dell laptop to connect wirelessly to the network. Both PCs connect wirelessly to the router now, but neither can find the internet through the router. The DSL modem shows no problems, and the "internet" light on the router is on. What should I do? The network always worked fine without the master ethernet computer connected... Does it have something to do with the fact that it is no longer connected to the network? Do I need to setup a new network with a different PC as the master?

Thanks for reading to the end, by the way