You do not have permission to change the status of this item

Hello,

We have a custom workflow for project change order approvals.  The workflow activity history shows that the workflow goes through all the approvals, then calls pa_control_items_workflow.change_status_approved.  Instead of changing the status to approved, it changes it to working, and the "You do not have permission to change the status of this item" error message is logged in WF_ITEM_ATTRIBUTE_VALUES.

I cannot figure out why this is happening.

Is the person who initiated the workflow the one who cannot change  the item, or is the person who gave the final approval the one who cannot change the item?  What is the item in question?