Often if you have a bad connection there will still be enough signal to make the router say it has a connection. The router does not test the connection, it simply ensures there is a signal. Odds are there is a problem. Redo the connections on the wires, if this does not work then go buy a $20 connection tester. They can save HOURS of time knowing what is wrong with the wire.
I hope that helps, for other basic computer advice and how-to's check out www.burnscomputers.com
I hope that helps.