[roddybug]

Perhaps Choc was after your mouse? [img]smile.gif[/img]

The invisible thing may've been an archer (or slime) shooting you from off-screen. It's a pain to pinpoint where they're firing from sometimes. I have had problems with everything going invisible sometimes, but that was a game/graphic card issue. Changing to a different dungeon level (if possible) or restarting NWN fixed it for me on every occassion.