Netgear dgn 2000

Hi,
I'm new to these forums, and equally new to Mac's, so I hope you'll forgive me if I don't include salient information, or miss the obvious. I have a problem with an imac 20" connecting to the internet and / or a networked printer via a Netgear DGN2000. The printer is attached to the router vie the ethernet hub, thw imac is attached both via ethernet and airport. The problem is this, with the ethernet cable plugged in, I can print, but I can't get web pages up (they appear to start to load but then stop before anything has actually appeared), with the ethernet cable unplugged, and using only the airport, I can access the internet, but I can't print. I have no idea what is going on, since my macbook is working fine, it is connected wirelessly and can print and access the internet, and all the windows laptops in the house are working fine (but I do know how to trouble shoot them a lot better than I do the Mac). I hope somebody out there knows something simple that I have overlooked. Thanks for looking.