No file access to file named.mdb after code break

Fellow mates Hi

Whenever a Back End msaccess .mdb fouls up eg by some unresolved codes in the Front End mdb, the task manager show no phantom msaccess running nor is there a .ldb (if ldb exist, it mean the mdb is in use by someone, thus no file access).

YET there is no file system access to the particular mdb. All other mdbs are not affected.

This happen in xwpin & win7. To keep thing simple all front & back are within the same PC eg C & D drive.
Moreover User have full rights to the mdb and Back End normally runs perfect.
All these is to rule out the usual security mistakes,as the probable cause. To me there must be something else.

Perhaps something is flagged by the OS to block file access. Only doing a re logging file access is allowed.

What can be happening behind the scene? Is there a way to check this state? Is there another way to revert back to normal