[ffcmike]

When you constantly receive Global PMs from people on Hidden servers, 99% of the time it's someone asking for scripting advise, then at some point while you're typing your reply they reconnect or log onto a different server, therefore they do not receive the PM due to the "Non existing player" error and you cannot locate them via the playerlist due to it being a hidden server.

I'd imagine this wouldn't be particularly difficult to fix, what's even more frustrating is when the person you're replying to happens to log onto the same server you're on right before you click send.