Debug information regarding BusyBee server (I haven't played the other servers recently):
I noticed sometimes a player is unable to use any commands in the chat. For instance, when you type !rules in the chat, the server does not respond, although the typed text appears in the chat. If one doesn't get an answer to one command, he doesn't get an answer to other commands either, no matter what command or whether one tries later. It simply seems in these cases there is some connection lost, although the rest of the game appears to function normal. I haven't seen the code of course, but to me it wouldn't sound too unlogical the server reboots after a while simply because this disconnection is detected.
Importantly, the phenomenon seems to happen right at the start of a game (or not) and seems to be a good predictor of a server reboot later. When I type !rules at the start of a game and I get a proper response, I know I can finish my game and when I type !rules and I get no answer in the chat, I am sure the server reboots after a while. The fact the problem seems to occur either at the start of a game or not at all is giving me the idea the problem could lie in the initializing part of the game code.
I have to admit my sample size is too small to drop any scientific conclusions yet, but so far I haven't seen any cases which contradict the above. Hence I thought it would be worth to share this piece of information.