I have not found the way to detect client crash, so the only way to prevent them is to block broken maps from voting. Another problem is the feature in TJMod to do it is broken: when the amount of blocked maps becomes large, blocked maps are no longer blocked

Moreover, I have installed a script (http://sourceforge.net/projects/qstat/) to automatically restart the server after few mins when it crashes. Server is now semi-protected against crash.

Thanks