Is it possble to make a copy of a copy?

[nuhnya]

If so, what am I doing wrong?
I´ve tried making a copy of Virtual Tennis selfboot, the burning reports no errors or other comments (using diskjuggler 3.0). When #####ing the diskcontent it´s no longer the same.

Are my settings wrong, is it not possible just to copy?

Do I have to remake the files to .iso or .cue?

Please help!!