I missed this thread
Not the whole gallery folder.
Folder(s) in which your images will be stored need to be 777. If the sever supports 777, some hosts only allow only 755. When doing a server "move" or "restore / re-upload" of all the media and sub-folders. All recursive directories must also be CHMOD.
The only reason to CHMOD 777 the "files" (used for FTP uploads) folder is if/when you do mass uploads via FTP.