Duplicate removal-RefMan v10-and missing entries

I’ve been working through about 1000 entries in RefMan 10 with many duplicates.  I’ve clarified the publication names which has permitted a large number of duplicates previously missed to identify via the duplicate search function.

Since I cannot do a batch-removal of duplicates in RefMan10, I attempted to export the file and reimport into a new DB, allowing the duplicate sort via import to handle that batch.

All went well until I noted the final count of files handled in the import.  My main Database has 930 entries.  I expected that many would be sorted on reimport.  My new db has 745, and only 81 were sent to my dups db.  Where did the remaining 100 go?

Is there an ideal export mechanism to ensure all of my entries are exported to a file (which I assumed was the case in the beginning).  Is this a known problem?

Thanks.-Ed

EDIT: Reset the db using original queries from multiple DBs using a filter.  Still no idea on the original problem, but my workaround was successful.