maybe try uninstalling mIRC and getting a clean copy? or could the prob possibly be something mucked up in windows which in turn effected mIRC since that was the app he opened?
i read several places, and all implied it was a memory allocation prob and/or related to a corrupt dll ... which is why i asked if he had added a dll or script. I see your point re the code, but would help to know if ALT did anything relating to dlls at all about the same time.
ALT: did you? and is mIRC the only app you are having a prob with? What OS? Can you think of anything you did/added just before this happened?