IIRC, there is a setting for the "Z" position of the item, be it painting or whatever. If that setting is not altitude adjusted, the object will fall until it reaches a surface to stop it (table, floor, etc.). It has been a long time since I messed with TESCS, but that is what I remember. Hope that helps.
EDIT - I just noticed the date of the OP...
3-1/2 years ago!.

I hope he got his problem solved...