Hi Fran.
There's nothing wrong with the reliability factor. If you had of had a PS2 keyboard with you, it would have been no problem at all. Something obviously happened when the keyboard was being shut down. Maybe someone pulled the plug too soon.
Either way, your obviously running on an old OS. This cannot happen under ver 5.0. You never need to have a PS2 Keyboard with you any more, and the shut down times are just a few seconds now.
Regards
James