Idle Telnet Timeouts

Not sure if this is the right list to ask this on, too many to choose from and none of the others looked like what I wanted. Anyway; here's the deal, I'm running a TinyMUSH world on my system. The problem that I'm having is that when a player is idle for any length of time they get disconnected with a "Network error: POSIX error: Operation timed out" as far as I can tell, this shouldn't be happening. Neither my ISP nor the MUSH software is disconnecting them. In fact the MUSH has an idle timeout in it to d/c players that have been idle for too long, this isn't activating however.

Anyone have any ideas on how I can stop this?