Well I havent really played the SP much, but I'll go on about the MP a bit:
- Whispering in lobby: It keeps changing players who you are whispering to, so you end up giving the pass to the next player accidentally. Ive noticed that you can stay in whisper mode and just click on another player, click back and it should be ok again. It seems to keep dropping down to the player under the player you are trying to whisper to.
- Lag Stops: If a player is lagging (I guess this is the cause), the game just stops. Sometimes it restarts, sometimes it doesn't - this bug happens to me in half the games I play and you need to just abandon it. BIG problem.
- Quitting games: You seem to need to quit to Windows every time you leave an MP game that hasnt finished properly. It wont let you retire the game in most cases.
- The dreaded "grey" games: Seems to be caused by either firewalls or routers on the hosts computer. Basically, these people can't host games at all - this accounts for about half the playing population at the moment.
There are more which I'll try to add to as I remember. Basically, the multiplayer is currently bugged to all hell. Its awesome when you can actually play a game, but unfortunately, this is limited to about 1 in 3 or 4 games at the moment - the rest have something wrong with them. I hope the release version is a bit more stable.
edit: sorry, just let me add that I LOVE the game - Its just frustrating at the moment playing MP caus of the bugs.