At the beginning of the game, I quit the furnace, climbed the stairs and Joey said something about the furnace (which I don't remember). Then he just stood at the top of the stairs and didn't follow me. Eventually, I got stuck and when I looked at the walkthrough, I learned that in order to advance in the game, Joey has to follow Foster. So I restarted the game and now he's following me; everything's ok. Strange problem though. Anyone else encountered this?

Didn't have that happen when I played, must be a random bug. I have to say I didn't actually encounter any bugs or crashes with the game on my playthrough.

Yeah, Joey won't go back into the furnace. I don't think he has to though. Also, he might follow you if you go around into the workshop from the other way. I just noticed that it's another way to get the wrench (instead of distracting the workman, you can wait until he's eating his sandwich.... although then of course you won't get the sandwich)