Here are two little issues which really don't matter that much to me, but maybe it is a good idea to mention them.
Often, when I host a game but them swap to something else such as Internet Explorer (when I am often reading the forum or checking e-mail while waiting for someone to join), the sound of someone joining my game does is never heard. So, I have to swap back and forth to check. This is happening under Windows XP, SP3. It doesn't always do this, but it does happen often.
The other issue is that when I host and a few people have tried to join but maybe stopped trying or whatever, or I did not accept their offer, the game seems to become unresponsive (the screen won't change, I can't exit the hosting, etc.). When this happens, I have to end the task. This seems to happen often, also.