Disklavier

I had a question about one of the disklavier utilities in the file 
vault.

I am interested in backing up my Yamaha discs so that I can have a 
copy just in case any thing happens to one of them. (Discs don't 
always last very long.)

I noticed that there was a program called dkvcopy as one of the 
disklavier utilities.

I tried using this software program to copy my sampler disc (just as 
a test) onto a blank double density disc, and for some reason, it 
just copied a bunch of garble.

Is it something wrong with my computer or is the sampler disc 
different from a normal disc.

Also, my Disklavier WILL read high density discs. Will the software 
support copying onto a high density disc?

Finally, maybe I am just parranoyed, but is there anyway that my 
computer would accidentally erase a Yamaha disc? Are the discs copy 
protected so that nothing can happen to them? They are expensive so I 
just wanted to make sure nothing could happen to them.

Thanks in advance!

-Rob