The problem has to do with a lot of underlying issues, I think. Hiding the window just hides the symptom, not the problem. I could be wrong, but the complaints were coming from the fact that mIRC corrupts data (scripts, logs) if it takes too long to close during a shutdown. In this case, Windows will forcibly kill the process, screwing with the way mIRC keeps file handles open to scripts/logs, and corrupting data. This is still an occasional complaint, but I imagine if mIRC used to stay open longer, it was probably a bigger issue and prompted the reversion.
