Have been playing with the new beta for a couple of days. The file warning dialog doesn't tell you in the overwrite file prompt if the file you might overwrite is the same, unless it's being shared. How about changing it to compare hashes when filenames are the same, and if the files are the same just say you already have the file, with an OK button and a don't show this again checkbox. If the files are different, the usual overwrite prompt appears.