Dear Splashdamage,
Is it possible you make and update on the some ingame commands,
like !shuffle, !putteam, !lockteam,or a lockplayer command like in Enemy Territory?
Most of the time when some players leave a team its hughely under balanced.
Seen it many time that the teams are, 2 vs 7, not counting bots.
Players in the weak team leave the server because of that.
The next who joins may face a 7 vs 1 team.
This kinda kills a server population.