Problem Statement
When gift certificate search is done two different gift certificates were present on store with same serial number but different amount. When the cashier tries to use the gift certificate at the register it shows invalid card.
Environment
iVend 6.6 with SAP B1 9.2
Symptoms
Cashier issued two gift certificate from two different stores with same serial number.
Resolution/Work Around
The gift certificate was user defined and inter store transaction was on. Same serial number gift is used at two different stores and because of inter store transaction gift certificate replicated to other stores. That is why duplicate gift certificate was showing on store.
No deletion of duplicate data or any data correction is done because it could disturb the iVend functionality.

Note/Suggestion
In this case to avoid this either system generated gift certificate or pre-printed gift certificate should be used.