I think I have identified a bug when playing a game on the online server while simultaneously playing another game via old pbem (manually sending the pbm file to your opponent). The bug happens when you save one type of game in the middle of a turn, then begin a new turn on the other type of game. The bug causes the second game to convert to first's game pbm type (either server or old pbem). Below are two examples of what happened to me:
1) While playing an online server game (Barbarosa), I saved in the middle of turn 2. I then restarted my computer and loaded a new turn sent my opponent in a pbem game (Europe Aflame). After completing that turn, I reloaded the Barbarosa game and completed my turn. When I ended my turn, instead of the game automatically sending it to my opponent on the online server, it had me save the turn as a pbm file. I did not notice at first, but eventually went on the online server and saw that my turn had not been sent. I contacted my opponent in the online server game and sent him the pbem file, but it asked him for a password (which he obviously did not have because it is an online server game). Because there was no way for him to open the file or for us to convert the pbem file into an online server turn, we have had to start completely over.
2) After starting over on the above Barbarosa game and beginning Axis turn 1, again saved midway through the turn and loaded a new turn on the old pbem game (Europe Aflame). I went through that turn, but when I ended my turn, the game said it was sending it automatically via the online server (which was impossible as this is a simple pbem game). The game did not otherwise save the turn that I could find so I could reload and I was forced to replay the turn (which luckily did not involve any real combat). When I agains completed the turn, it worked as normal and produced the pbm file that I could send to my opponent.
It appears there is bug when moving from one form of pbem play (server) to another (old - email). I have uploaded the save file from midway through the example #1 turn above. This turn should have still been an online server game, but at that point changed to a old pbem game.