Duplicate File Finder - Duplicates wont delete

I have run Duplicate file finder across two folders on different drives. A large number of correctly identified dups have been found and marked with the red cross. I have used MD5 and Delete mode. When I request Dopus 10 to delete (using the delete button in the side panel) I get a warning window 'that I will be deleing real files'. I agree that but then nothing happens. What am I doing wrong?

If you turn off Preferences / File Operations / Deleting Files / Delete to Recycle Bin where possible (supports undo) and Apply the change, does the Duplicate Files pane's Delete button work then?

(Remember to turn it back on after testing, unless you want to keep it that way, of course.)