In order for a running balance to appear next to an item transaction, the transaction must have been entered using version 3.
Running balances aren't available for item transactions recorded using a version of MYOB AccountEdge previous to version 3 because the inventory audit trail feature was introduced in version 3.
In MYOB software previous to version 3, inventory transactions could only be viewed in the Transaction Journal window. A running balance isn't available for those inventory journal transactions.
In addition, the date of the transaction must be the first day after a purged period (if you've purged transactions from your company file using the Purge command) or later.