I've also had this problem reported to me on my forum as well; it's not caused by the garbage collector cleaning out the session file before the user has finished the game is it?
The default is only 24 minutes, and this was the case on my server. I've just upped it to two hours for testing, and I've got a user who is always complaining about it so I've asked him to retest
OK, user has retested and says it is working now. Obviously I can't be positive about this, but it might be worth a try for those with issues
Two possible solutions;
Firstly server admin can edit php.ini and add...
session.gc_maxlifetime = xxxx
where xxxx is a value in seconds. Then restart the web server. This is obviously server-wide however then.
Or;
The mod code could be edited to do this at runtime. There are complications with doing this, a good article on it
here.
HTH someone