For anyone who is interested, here's how to reproduce:
In ArcCatalog, create a new mdb and a new point feature class in it. Create one field that will be editable in your feature class (I just made 1 text field) Edit in about 4 points with geometry only. Add globalids. Create a folder for your cache. Save the layer in an mxd. Run the geoprocessing tool Create Mobile Map from the mxd. Go to ArcGIS Mobile and open the project. Edit the attributes of the field you made only. Close out and go back to your mxd and run the Synchronize Mobile Cache geoprocessing tool, choosing to upload changes but not download. When you refresh your screen, some of the points will have jumped on top of other ones.
When I tried it with a gdb I did not have a problem, yet.