We are running ESET Smart Security 4 Personal Firewall on a windows 2008 server with Mysql running on port 3306. We have made a rule for incoming connection on port 3306. When the personal firewall is set to automatic filtering mode, the Mysql database can be accessed for a number of hours, but after a while we get a message in the log file saying "No usable rule found" and designated port is 3306 and Mysql cannot be accessed. When we switch to interactive filtering mode we can access Mysql over port 3306 without any problem. Any idea what the problem of running in Automatic filtering mode can be?