So the administrator can open the document. It is technically ok.
The users can see the document, but are not able to open it? Then you need to give them access on the report. This is done in WebAnalysis on the properties of the document. I don't know which version you are in, but sometimes it is hard to see where to click in the row, once you have selected the group / user.
Read access should also protect from moving and deleting reports.