Just like the title says, when I replicate my two deployment shares, i get the "Name already exists:'\\MDT_Server\mdt_production$\Operating Systems\Custom Windows 7 Enterprise x64\CRE_REF_64DDrive in CRE_REF_64 CRE_REF_64.wim' specified." error.
However when I go to that DFS route no folder called "Custom Win 7 Ent. x64" exists or can be seen. (hidden files and folders are shown.) Also My x86 version copies across error free.
side note I know "linked deployment shares" arent the best way to do it, but its the way it is set-up and its staying the way it is!
More about :mdt linked deployment share exists error
Are you trying to put a second image in your WIM with the same name by chance?
If you're stictly working within DFS, I would manually delete the files on each share (actual and link). But the error seems to be pointing to a name/file/folder in your WIM.. which if you're using DFSr then it's replicating at the bit level. If that's the case, I would suspect an issue within your WIM file itself.