You didn't tell us what OS you use. Windows doesn't properly differentiate between uppercase and lowercase. So it considers jack and Jack to be equivalents. I don't know how Windows does renaming, but in the *nix world, there isn't a "rename" command; it uses "mv" (move). So moving from one folder to another, where the two folders' names resolve to the same value would be a logical impossibility. Maybe Windows uses the same method under the hood. I suspect that OSX and Linux would have handled this more intelligently, because they would see jack and Jack as distinct and different names. In changing it via an intermediary and different name, you have done exactly what I'd have advised you to do.