There is a collision bug in the mission The Return of Ur.

As shown in these two screenshots, my knight in d21, running under the two lamp posts, and was stopped by some invisible obstacle, almost like there's a block at the bottom.

http://i.imgur.com/gxwLa.jpg
http://i.imgur.com/nj3AT.jpg

Those almost got me killed.

*Runs*
Me: Whoa, why am I stuck? Lag?
Devilites: Bullseye!

Please either remove the obstacles, or make them visible.