I have 2 Windows computers and 1 Android phone all signed up with my Dropbox account.  I want to delete some old photos from my Dropbox account (I already have them manually copied to a different archive folder on my PC that isn't linked with Dropbox. )  When I delete them from the Dropbox folder with one computer, they aren't getting out of Dropbox folder on the other computer or the phone.  I wind up with files that have names saying there was 'contention'.  Do I have to delete them from the web-interface to Dropbox?
Deleting Dropbox files from PC, phone, and web
dropbox