We are having an issue I have never seen before. A user keeps getting locked out of his model and loosing work when another user opens a drawing that is xref'ing his model. We have checked every autocad variable that relates to locking an xref, and everything is correct. The lock file being written into the directory with the model is a MS Access LDB lock file, which is coming from the Bentley database for the project. Sometimes the user referencing the model just has to close his drawing and the lock file goes away. Other times they have to shutdown completely. On a few occasions that didn't even work and changes to the model were lost due to the person not being able to save it.
I should note, that the drawings that are referencing the model are for annotation, so the database is being queried for the Line No and Coordinates.
What could be causing this lock file to randomly get written into the directory and locking the model? This is not an autocad xref issue.