I have the Sibelius disc you mention below. I picked up used in Orlando, and it is a BMG issue. I played it as recently as a couple months ago and it played fine.
I don't know about DG, but I would almost be willing to bet that the BMG Club wouldn't be able to help you. This disc has been out of print for a while (if its 427 647-2 were talking about with the waterfall on the cover, right?), and I can't imagine them keeping extras on hand.
Dana Hill Gainesville, Florida
http://www.danajohnhill.com