What is it with Wait(), FadeToColor() and LeaveAreaLUA()?

I'm using the last of these actions to move creatures around. FadeToColor starts first to cover it up, but with the LUA the blackness lasts 10-15 seconds, even without a Wait(). In fact, I removed Wait() to shorten the time a little, and it's still too long. The game action has resumed, FadeFromColor was written to go off quickly, now characters are talking, music is playing, but all is black. This is similar to the problems I'm having with AdvanceTime() - either in combination with FadeToBlack or by itself it invokes a long blackness. Has anyone else noticed this?