Perhaps you're in need of an update on the program? Are you running the latest version? If you are unsure, I can get you the link to a combo installation of mIRC and invision. Invision is a plugin in for mirc that let's you use a somewhat different interface to access the board/chat/files. It's sooooooo cool! No more typing in dos commands.....simply click your way thru. It even talks to you to tell you what's going on.
I don't know why you're having problems...I have not ever bee just booted from the system unless there is a netsplit, and then everyone is disconnected for a very short time....but then it re-connects you without you having to prompt it. Maybe you should give this other thing a try? I"ll pm you with info if you're interested.