Airport Elevation Changed and Buildings are Floating in the Air!

Hi guys,I hope someone has an answer to this one. I just upgraded FSXs scenery with FS Genesis USA terrain mesh and Landclass, F1's Ultimate Terrain, and Ground Environment X. In my FS9 installation, I also had FSG's terrain mesh and Landclass, FScene textures for the USA, as well as Ultimate Terrain for FS9. Things looked great and my local airport KAVP was accurately depicted. It sits up kind of on a plateau with small drop-offs on both sides of the main runway 4/22.After installing everything in FSX I decided to explore. For the most part elevations looked pretty accurate for my area in PA except on approach to RW 4 at KAVP I noticed it no longer sits on that hill with the dropoffs but rather is pretty even with the surrounding ground. As I taxiied in, I see autogen buildings around the airport are floating several feet off the ground!! Any ideas what's happening here?? Thanks. Tom