I'm not sure, but I believe this started happening for me when I started denying dest-unreachable icmp packets. I'm guessing a firewall could be preventing TCP control messages from reaching the client, such as "sorry bud, but an error occured and we're severing your connection". If the client doesn't receive this, it just sits there oblivious that there's nothing being sent anymore.
What I find interesting is that mIRC only realizes it has been disconnected when you try sending text to a channel or query, but it doesn't realize this when it sends an ISON command every 30 seconds to update /notify. Perhaps Khaled could make mIRC check the connection if the server fails to respond to ISON and any other command for several seconds.
- Raccoon
