I'd like to bump this topic, especially considering some of the Hamachi changes I've heard about. Have people tried this patch? How has it worked?
After going over the previous log files in more depth, it appears that perhaps not all players were using the latest patch. The current version should be backwards compatible, in that older clients should work as they did before, but that also means the benefits of the latest patch may not be realized unless everyone in the game has upgraded.
Edit:
Ok, subbed74 and bmenrigh have helped me do some testing, and no problems were logged or occurred during our tests. I did a couple of 2 and 3 player games with subbed (who was using two computers from the same IP address), each of us taking turns being the host, and then a 3 player game with all of us. We checked the logs between every game, and everything showed up clean.
I would be very interested if people who have had trouble with the patch in the past could report how things work out when all players have the latest patch, and how many players were in the game. In particular, there are certain problems that are unlikely to crop up until you have at least 3 players. Any reports, positive or negative would be appreciated.