Doesn't sound like the router is at fault. If you have access to another computer (or a friend's) and it can log on OK then we could confirm it's just yours. If that's the case then you or your friend can go to this website:
http://cexx.org/lspfix.htm and click on the file LSPFix.exe (not the zip version) and save it. Then run it on your computer. Press 'Finish' even if no errors are reported. Restart computer again and try to get on line. Report back if nothing works and I'm sure others will be along with ideas.