limited or no connectivity with wireless, but local area connection works

Using my rj45 ports with a cat 5 cable I connect to the internet with my laptop with no problems. I do not even have to set up a network with xp; I just plug into the router, which is connected to the dsl modem, and voila I have a Local Area Connection.

When I disable the Local Area Connection and enable the wireless connection, I have no trouble finding my wireless router signal and connecting to the network. However, I get the limited or no connectivity popup when my computer tries to aquire the network address.

When I click Repair connection, I get "cannot renew ip."

Any thoughts?

I forgot, my main reason for posting is that I cannot use the internet with my wireless connection. I can only get it to work when I connect with the cat 5 cable.