Watchdog timeout

Sometimes, and lately very often, my m0n0wall firewall outputs the
string "watchdog timeout" on the screen and all connections drops.
The only way to have any connection back up is to restart the firewall.

Tha fact is that I donn't even know what watchdog is and what it means.

Can anyone help me please?

P.S. I beg your pardon for my English if I made any mistake.
--
Michele - Too far from America
MSN ID: myksto dot hotmail dot com
"It's the world we live and life in general..."