You want to ensure the documents are visible from the relevant timesheet or placement, then check that the client is configured correctly by following these steps:
Click the Setup menu and point to Clients.
Click Client Maintenance/Client Search and find or open the relevant client record.
Select Print Documents with Invoice? or press Ctrl+M to enter modify mode if necessary.
Select the Regenerate Print File and Print Document Images? checkboxes.
Reprint the relevant invoice(s).