It might have helped if you said which version you were referring to, FS9 or FSX.
However, I've checked both sims, and there are no problems with the scenery at dusk (which nobody reported it before, anyway), both in FS9 and FSX, see the screenshots.
You can try removing the file, and reinstallin the scenery, so it will restore it.
If still doesn't work, most likely is a conflict with another product that has VTP scenery for the area ( UT Europe, perhaps ? ).