It may be worth complaining to your ISP and have them take a look at your stuff... This winter I was 90K about once an hour every night for 2 months straight even though everything else in the house seemed fine, so I assumed it was the game. Then all of a sudden one week everything in my house was having issues, Netflix on PS3, youtube on wife's laptop, etc. They finally set up an appointment after the 3rd day and when the guy got there he said they were replacing a bunch of stuff at the main box for my neighborhood and also replaced all my equipment inside. Game has run pretty great ever since.

So, if you have messed with Firewall settings reset your equipment, etc etc - I know it could be a long shot and won't work for everyone but it does seem that this game is a bit more sensitive to internet than other stuff. You may try replacing a router or get a new modem, worth a shot.