History records of Power Pick transactions are stored in Power Pick's database, which ItemPath accesses through the API. If you are not seeing some old transactions in ItemPath, it is likely that they've been archived in Power Pick.
The number of days Power Pick stores data is configurable within Power Pick. The purpose of this is to keep the database from slowing down because of hundreds of thousands of records.
For assistance with changing Power Pick settings, contact your Power Pick administrator.
