Help with connecting to linksys router

Hi, I have a linksys wireless router, and Im having trouble connecting to it. Everything was fine until about two weeks ago, where all my utilies (ipod touch, macbook pro, xbox live adapter) stopped connecting. All of them recognize that my router is sending signals, however I can't connect to it for some reason. I don't have any security password up, so it isn't a password thing. Another note, is when using my xbox live adapter it says it can't obtain the ip address for some reason. I live by a lot of wireless adapters from all these restraurants near by, I don't know if they could be causing any issues with this. Please help!

 

What do you mean by renew the DCP lease? Sorry, a little un-computer friendly.

 

Hey, one more thing, the computer I have right now is connected, but everything else like I said won't connect.