signal for only a couple of minutes

I bought a Linksys wrt54g and configured it and running hardwire wit my dell. now the thing is when I connect my macbook to the router itll get a signal for a couple of minutes then it will lose connection. But still says that i am connected to my router. ALso does the same thing as if i wasnt running a secured signal. I would hit the reset button and itll get signal but for only a couple of minutes then loses connection. Can it be a problem with the router? Im a noob on the wireless scene :headphone Thanks in advance