Why do some item transactions have no running balance?

Inventory > Analyzing inventory > Using the Items Register >>

In order for a running balance to appear next to an item transaction, the transaction must have been entered using Version 3 or later.

Running balances aren't available for item transactions recorded using versions of MYOB AccountEdge earlier than 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 used the Purge command) or later.