Originally Posted by broke

This will create and mount a case-sensitive disk image (a 5 MB case-sensitive non-journaling HFS+ volume, if you must know) whose volume name is "CaseSensitiveTest". Now copy a small file onto the disk image, then open the disk image, duplicate the file, and give the copy a name which is identical to the original, but with a different set of cases. Now drag both files onto the desktop. You will get an error from the Finder which has the exact same icon and message as shown.