Game drops my friend and I after playing for awhile.

Every single time my friend and I connect to play, we are able to play for about...30 minutes or so (random amount of time really but never longer than an hour) before the game quits and gives us both "victory" messages and tells my friend and I that the other player disconnected. Why does it do this? I cannot understand what is going wrong.

It also seems to be worse since the new 1.05 patch has been released.