UltimateTerrain USA users experiencing bumpy taxiways can follow the instructions below to resolve the problem.
In the main FS menu, Select <SETTINGS>, <SCENERY LIBRARY>
Scroll down until you find a entry called "Seattle Aerial Photo"
Select the "move up" button repeatibly until the Seattle Aerial photo shows
above the entry for Ultimate Terrian _ USA.
Restart Flight Simlulator & the taxiways should be smooth.
