Character stuck_Feralas

While digging in Feralas, i run in a trap of invisible walls. There is no way to get out from there (except hearthstone). Within the walls, the area is about 4x4 meters.

Picture:
http://img213.imageshack.us/img213/6439/wowscrnshot091110133542.jpg

Located in Feralas at the northern ruin from ruin of isilden.