I definitely agree that as far as "the players going the entirely wrong direction," this is definitely one of the big winners. It's one thing for the players to waste a session, say, chasing red herrings in a murder investigation. It's quite another for them to do the same thing chasing a non-existent elevator in a ten by ten room.I suppose what made this stand out for me above typical garden-variety failure was two things.
Firstly, their utter conviction that this room was a puzzle with a solution that they couldn't find, and their refusal to be shaken from that (as noted, even in one case after I did make the OOC point that the previous occupant could fly). There was even talk of going backwards through the rest of the dungeon on the assumption that the trigger mechanism must be back there and they'd missed it.
Secondly, the fact that they were just kind of striving at nothing. It just felt a bit like they'd walked in to a room, decided it was filled with invisible ninjas (based on no evidence) and then spent the rest of the session trying to detect them, with each failure just reinforcing their belief in the ninjas and the threat presented by them. The repeated attempts where they were trying to figure out how to use a table to ascend the shaft were very much in this vein... (in fairness to the party I should point out that it was a magical floating table)
I dunno, maybe its one of my failings as a ST that I tend to indulge players when they do things like this a little too much. Focusing on this stuff, instead of actually moving the story along and such. It's one thing to fail to stop the invasion of the horseheaded aliens from nebulon 5, and its quite another to fail to find 35 cents in loose change by riffling the cushions at your apartment.
Plus, of course, the storyteller getting frustrated isn't any better than the players getting bored in the end.
Oh, and the room with invisible ninjas? That cracked me up