I was not able to find the exact report you show, but I used a report called unbilled time and unbilled charges.  In both cases, I selected all dates and nothing shows up for the project.  I try and delete the project and again it gives the same response.  On one project, I got the message and just tried to delete it again and it did the second time.  I went back to others and tried to delete it more than once but got the same message.  Any other ideas.