Running a Powerbook G4 with Leopard, and it works, albeit strangely. When I downloaded a fresh 2.0 version of the app and installed on my system, what I got was a folder, instead of an app. I opened the folder, opened "Contents", opened "Mac OS", then launched "Hi-MD Music Transfer", which in turned launched the Terminal as well as the app itself. The Terminal sat there and logged everything the app was doing. For some reason, Leopard isn't seeing it as an application package but as a folder. It works, though! Whew!