CRM Custom Report stored procedure returns incorrect results

I have a custom report loaded successfully into CRM, been working fine until last week. Now, it is returning inflated results. I have isolated the date that the results are being inflated in the report in our hosted Production environment, but cannot replicate the issue when I run the same query from the stored procedure in our DW read only production copy. We are not able to actually execute the stored procedure in the DW read only, so I had to remove the query from inside the sproc, to be able to test the report results. When I do that, the testing gives me the expected results, and not what is given in our report when it is ran from our production environment. Any ideas?