This item cannot be deleted because it is still referenced by other pages

I have a master page that won't go away...  You will get "This item cannot be deleted because it is still referenced by other pages" errors from SharePoint Designer and WFE.

I tried
1) putting in temp folder then deleting the temp folder - did not work.
2) Go to the Properties of the Master Page you want to remove
    Go to Content Type > Page Layout and set it to _Hidden.
3) Also tried naming and putting in another folder
4) Tried renaming to .masterX, still nothing

Its still there...