Referenced file gets scaled after re-opening the scene file

[sladkova.a]

Hey you beautiful people! I have a scene where I use two referenced files. They are grouped together. That group is animated. All works fine till the moment when I close the scene. When I open the scene again (after several days) one of the references appears scaled and off its position. Scale value is not animated on any of the nodes from the scene hierarchy. Reloading the reference doesn't do the trick. Referenced files has no history, are in the world 0 position. 

Any ideas what might be the cause?

[hamsterHamster]

Too many variables and unknowns to generate ideas productively -- could be issues in either of the referenced files or in the main scene itself, e.g. some unintentional reference edit records that might have occurred during scene setup/hierarchy building (check edits list in RefEd for the drillbit reference). Also I'd suggest using MB format for the main scene (or at least make milestone backups as MBs).

Otherwise provide at least that part of the scene with GEOMETRY structure, i.e. references included.