Well, there's a wealth of evidence that firewalls do work, if they're not working for you then perhaps there's a fault at your end? Perhaps they aren't set up properly, or, as I predict, you have other insecurities on your computer that people are exploiting.

Make sure all you're software is up to date, make sure you have all available updates from Microsoft Update (www.microsoftupdate.com) and ensure you have 2 or more antiviruses installed, run a full scan on your computer with them, and then reboot when requested by those programs/websites. For suggestions check out the this thread.

If someone is that determined to hack your computer then they will do so, but I have very high doubts that you have encountered people who are that good. Sounds like you've simply encountered one of the army of kiddies out there who is taking advantage of a common exploit on your computer that you probably know nothing about.

Either way it has nothing to do with mIRC the IRC client. mIRC just connects you to IRC. The channels, people or networks that exist on IRC are under no control by the developers, testers or other users of mIRC.

Good luck though!

Regards,