I finally figured out why. The price of 'archival' DVDs has fallen below the current price of CDs, so low that packaging and shipping is probably a significant part of product cost. I ended up buying a spindle of DVDs instead.
CDs are quietly disappearing. Alas, I should upgraded my mother's new Mac Mini to a DVD burner! Blank CDs will become increasingly unreliable and costly.
I remember reading the book written by Bill Gate's father (yes, his father) called 'The New Papyrus'. It was all about the how the data CD would revolutionize the world. This was before the net became public. I was amazed by the CD back then, and I wrote a letter to a Canadian development organization on how it could dramatically change the delivery of knowledge to what was then called the 'third world'.
Good-bye CD. We barely knew you ...
Update 9/25/09: See also - UK University lectures and iTunes U.