It may be the same issue I had for a while. Check out the router firewall log and see if your I.S.P I.P.s shows under DoS attacks. My router reported numerous bogus DoS attacks. Every IP listed was from my ISP. I had PPoE at the time. They lessened when I got DHCP instead. They went away completely when I put my TA as the firewall. I take it people with a static IP do not experience this issue as much.
