I did not understand your idea. If you cancel the copy it won't finish, of course ! Can you please write your idea again ? Sorry if I am not being correct with you, but I really don't understand that.
It will freeze @ x% on certain FW versions. It is very strange. The two files libmpg.mpg work very differently after each firmware update. (Almost like its saying don't tell me that) BUT I know this file is useless now, unless we can figure out why it casts these symptoms to the system.