I have a 2800 router that works just fine with about 50 PCs and 1 other Mac. When I connect the new iMac 27" to my network I can't get to the internet. It shows all the correct addresses and can see everything on my LAN, but can't see out past the router. If I put a cheap netgear router between the iMac and the 2800 and double NAT, I can get to the internet. What could be wrong with the router, or iMac? Could there be a firmware update for the router? All of the updates for the iMac have been applied, and it's running 10.2.6. Any ideas? Thanks.