That's interesting. I haven't noticed this happening here yet. Do you have "Elevation Exaggeration" set to '1' in your Google Earth settings?
I have "Elevation Exaggeration" set to '3' here, which makes the terrain more realistic.
The problem I noticed is that the different properties have different settings which makes them appear at different heights.
e.g. the path/trails have the "Altitude" set to "absolute"
while the model has the "Altitude" set to something different (it appears as "mixed modes" but that doesn't seem to be a "defined" option).
If all the attributes used the same value, then everything (models/trails etc) appear at the same height. The "relative" fields seem to give the most realistic looking positions.