thanks, TPEG, i didnt see the "static", and i think you didnt see the "small/medium...".
but normally cant be because all the statics are blended together in the universe.dbo as 1 object that loads completely when you start the level.
what you describe happens all the time with decals and particles, but i havent seen it on statics.
@timon:
are you sure on the statics, or do you mean immobile?
when you place the objects on the next ground using enter-button, it happens sometimes that they dissappear, depends on the center-point of the object. try to level the object slightly up.
maybe it helps.
also watch out that they dont reach out of the map, so leveling down an object on heightlevel 0 is not a good idea.