ooo, that's cool... so we did have a problem, years ago, with Actiontec cable modems that had buggy nat f/w code that couldn't handle two TW sets behind the same NAT because they were connecting to the same mbg ip/port... I certainly hope this isn't what you are seeing as there was no solution aside from a, eventual, fix from the manufacturer... I think our customers ended up switching out modems at the time. A tcp trace of the traffic on MBG ( tcpdump ... host mbg-ip and tcp and port 6801 ) and one on the set side (if you can get a ethernet hub in there, PITA I know) would be nice to take a peek at to see what's going on.
Do other set types work? is this only a problem with the turret?