Maybe this has just changed and I simply don't get it now, but this (nor the other) special door in the Mines of Zakiim does not open. You get the echo and lose the bar, but nothing else changes. I distinctly remember it opening before (years ago) by using the bar... by design?


The Foreman's Quarters
This is a rather small room. The walls have been carved out of the rather
soft, dark sandy colored rock here. A large desk resting against the north
wall dominates these quarters. There is a large stack of papers pushed off
to one side of the desk. There is a small cot resting in the southeastern
part of the room, right next to a large, ragged looking dresser. A helmet
and a thick coat lie hanging right next to the cot, with a pick resting
against the wall there. Above the desk there is a small shelf with a few
books resting on it.


<425hp 502m 544mv><11042tnl><8 AM><civilized indoor> exa shelf
Various books are kept here, ranging from a book on basic geology, to
stories from famous poets and writers. More curiously, you notice a small
square shaped slot in the wall just behind the books, almost like you could
fit a key in there...
<425hp 502m 544mv><11042tnl><8 AM><civilized indoor> exa bar
This bar seems quite curious, not like some random piece of trash. It
is rather precisely cut, and about three inches long, and not even an
inch wide. Perhaps it could be a key of some sort?

A small square-shaped bar is a treasure, made of steel, and weighs 0 pounds 13 o
unces.
<458hp 502m 544mv><11042tnl><9 AM><civilized indoor> exa slot
You do not see that here.
<458hp 502m 544mv><11042tnl><9 AM><civilized indoor> use bar slot
The bar slides perfectly into the slot in the wall.
You hear a dull clicking sound from within the wall.

You're only half done with opening the door.