http://img841.imageshack.us/img841/5592/spiral20120204033723.png
http://img163.imageshack.us/img163/6928/spiral20120204033716.png
I was still able to pick it up after discarding a stun vial to make room. I've seen this glitch happen twice at the time of writing. The first time it happened with heat, so it isn't an item-exclusive glitch.
Can confirm this. Lost a curse vial up the "wall" of a level. It was on a corner of a staircase so the vial ended up floating, about twice as high as the above pictures.