Is it just a few pages duplicated … sometimes … then see below topic.
If it’s a lot of pages and always then as Jane noted it’s likely bad code loading the WMF’s maybe with Directory() rather than using the Report Preview(Q).
If you are going to print large Clarion reports you should regularly run a program on end-user PC’s to clean orphan WMF’s out of the Windows Temp folder. As you fill it up Reports run slower then fail to run.