How the scanned tag gets associated to the Asset

In the Fixed Assets Physical Inventory,while trying to Associate Tags to Assets with a scanner,we are able to see the scanned tag for the asset in the 'Enter Physical Inventory' screen.But when we runt he Reconciliation report,the tag number in the Physical Inventory is getting overwritten by the tag number for the same asset in the FA_ADDITIONS_B.Can somebody suggest how the scanned tag gets associated to the Asset