Linksys WRT54G Problem, Please Help!

Hi. My roommates and I recently set up a wireless network with the aforementioned router and have been having some strange difficulties. First off, only the person who set up the network has been able to connect to it. Secondly, not only can I (or my other 2 roommates) not connect to this network, it does several screwy things when we try. First of all, in the wireless connections box, in the top left corner when I attempt to connect, it will come up with "Not Connected" however, in the paragraph it describing the network it will say "You are currently connected to this network" and I don't have a connect option at the bottom, I have disconnect. Secondly, when I attempt to connect to the network, after failing, I will be unable to connect to any network at all until I restart my computer. I have been using the free wireless from the burrito place below me, and if I attempt to connect to it after having attempted to connect to our network, I am unable. Anyways, what should I do? Anybody know a quick fix here? Just let me know what information you need.

 

I'm going to repost this in Networking, not sure which it belongs in.