Ok, so maybe everyone here knows about the bug in Coal Chamber if you think, "Wow if I use Dimension Door after killing the Cube, I can cut my travel time in almost half, what a great idea." Except it bugs the quest and you can't complete because you don't trigger the necessary ambush.
Personally, I think the "challenge" in Coal Chamber is not falling off the odd ball physics or getting cross eyed going in circles. So Suggestions:
1. Put a warning up when someone casts Dimension Door like you do in Shroud where it says "Don't release, it's all part of the fun."
2. Recognize that you are penalizing intelligent play in a quest that is more than sufficiently frustrating as is and either:
a. Remove the ambush entirely
b. Make it an actual Optional, optional.
In before the Log out.