> And, what's
> even worse, is that it takes up a slot in your inventory and you can't
> sell it or drop it or otherwise get rid of it (at least, not that I've
> found).
If you go to an in and exchange one of your party members with another
character. (Not the one with the vault key!) You can then pass the
vauly key to that character and then swap him back to the inn. I use
this trick to get rid of useless gems. Even to stash items for later
use eg DB sword parts.
Jim