Comment 3 for bug 301749

Just wanted to comment I also experienced this: install theme, delete, re-install and error message:
"Can't move directory over directory"

So to re-install I had to delete it myself, but as I did not know where the themes were stored I had to search it first
and finally found them in my home-directory under .themes.
So not that even if a name clashed, it would be nice if the error message include the full path directory name.

As a workaround: deleting the corresponding sub-directory lets me re-install the theme again.