title: Cannot insert duplicate key row in object with unique index when there is no actual duplicate
body: <p>I'm getting a "Cannot insert duplicate key row in object" error when trying to insert a record which does not exist in the table through a SSIS ETL job. This error, however, does not appear when I put a 'where' clause to specify the exact record the job is complaining about.</p>
  
  <p>Ex., I'll get the error for primary key (100, 200, 300). I've confirmed that this combination does not exist in the source table, so I know the error doesn't exist at that level. But when I put a where clause that filters the source table to have records with just '100' for the first primary key field value, the job runs without errors. Could this be a buffer issue or something with the environment?</p>