Abacus Scenery Shortcut for FSX

does anyone know what im doing wrong? I am currently creating some scenery for Galveston, TX and have made an Oil company HQ's with 4 Helipads (1 on the roof) and a hospital with 4 helipads (1 on the roof) and some offshore oil rigs. Everything works fine except when i try to add people on the oil rigs or on the roof helipads. For some reason when i load the scenery the people on the rigs end up in the water below where i origianlly placed them but when im in the object placement tool they show up in their proper spot. I have people at the helipads on the ground and they show up just fine and in the right spot, same with the ambulances at the hospital helipads. Is there a problem with the scenery shortcut that will not allow you to place objects off the ground (i.e. on top of a buiding or on an elevated helipad?) please help so i can fix this and share my scenery 
