Solution out of CS149329 delivers wrong results !
It displays also objects that actually have a representation
Solved! Go to Solution.
I don't know, if it is still of some interest to you. I just fell into the same issue.
The root cause of the problem with the report is, that it also reports checked out data.
Therefore you need to add an extra constraint to filter the objects.
Add the Display Name "Status.Status" from EPMDocument to the report and run the report with the option:
Status.Status <> "Work in progress private".
That helped in my case.