i'm sure this will be easy to fix and since you are going to work with a new lighting engine, i wanted you guys to see this.
Also, i didn't know if you guys knew this, but there is a gap under the WF in Hourglass. You can't really tell with my ss, but it is a 2 foot gap and is easy to see when playing.
We use dynamically added doors at runtime, the shadows are static wich means they are done wihile compiling (for better performance). With the UDK we will be using not the same building-setup, so letz see if this will solve the problem.