well, it´s looks like being a matter of OBJ format. alltho vertex number is still the same after exporting the vertices have been counted differently vtx379 is vtx798 in the other model.

I use to model in maya and export to 3DSmax then. I found out that FBX is less stressful to work with then OBJ. saving/loading UVsets and transfering does also not happen to work within MAX. but one workaround was to use a morpher modifier and just turn the bad UVs into good UVs.