I have a Dell Latitude D420 with an Intel Proset Wireless Card.  When I'm undocked, the signal to my wireless network is fine.  As soon as I dock, the signal goes from excellent, to very good, to fair, and then disconnects.  It will find the connection again, reconnect, then disconnect again.  It won't remain stable.  Ideas from anyone would be great.  I've tried a different dock, same results.  Moving the dock to a different location doesn't do it, either.