linksys wrt300n router and cable modem problem?

i’ve got a ntl cable modem hooked up to a linksys wrt300n wireless router. The modem works fine using ethernet cable to laptop but not through the wireless router. I can connect to the wireless network and a ratio of 3 packets sent to 1 recieved is shown but i cannot open a webpage or msn etc. If i connect a ethernet from laptop directly into a modem port i can access the router config page. I’ve tried resetting the router but it did not solve anything,what could be wrong with it?

any help would be greatly appreciated 🙂