Slow moving from desktop to the appropriate folder

I have DZ on my iMac, no problems with ram or such.  I have reloaded actions and debugged console.  But this continues.  I have a PDF on desktop, not that large a document, I want to move to Folder A so click and drag onto the window and put in that folder and there's a little ping to say it's done but it takes 20 seconds before the item moves off the desktop [I timed it]  - so I can't be sure it's really in the folder.  I checked tho and it is.  So DZ may work and the ping happens but the item doesn't move for almost half a minute.