Please read:
http://packetstormsecurity.org/0512-exploits/mIRCexploitXPSP2eng.c[Editor's note: as far as I can tell, this is neither an exploit nor a vulnerability. The above report describes a local bug in mIRC. The author of the report indicates that any malicious software on your computer can modify your mIRC settings to cause mIRC to crash. But if you have malicious software on your computer, you've already compromised your security...]
