Might like to see the
Common IRC Errors post where it says:
"Servers automatically ping users at a preset time. The reason for this is to ensure the client is still connected to the server. When you see "PING? PONG!" results in your status window, it means the server has pinged your client, and it has responded back with a pong to ensure the server that you are still connected. When this does not happen and you disconnect without the server's knowledge, the server will automatically disconnect the user when it does not receive a response, resulting in a ping timeout. Ping timeouts occur to EVERYONE."Try installing a fresh mIRC without any scripts to ensure it is not a script interfering and causing this.
See if you get the same error on different networks. Try connecting to irc.undernet.org or irc.efnet.net and see how long you can connect then. Disabling any firewalls you have might help, and if you're on a router then disabling it temporarily might be an option, just to make sure it's not that.
Ping Timeout generally does not occur a few seconds after connecting, so it might just be the server you're connected to being problematic.
There have been numerous threads started about this issue so you might like to try using the Forum's
Search feature with the search term 'ping timeout' - expand to 'All Forums' and 'All Posts' for best results.
Best of luck!
Regards,