FSX and Generic Buildings

It seems that generic buildings in FSX do not place as expected. We already know that they 'float' at some airports but this is something different. The reference point of a generic building is at the center point of the footprint (unlike library objects where it can be located anywhere inside and sometimes even outside the footprint of the object). In FS9 placement tools will place the object exactly as it appears in the Sim. In FSX placement can result in an error so that the building itself is not located with the center of the footprint over the placement coordinates. So far we have not found a pattern that allows us to correct for the problem. This does not affect other elements like runways, taxiways etc etc. The only explanation we have so far is that it may relate to the 'round earth' model introduced in FSX. The only solution (as for the floating buildings) is to replace them with a library object.