How does copy protection work? This excellent article from NewScientist, which informs the world that copy-protected CDs are a waste of time, explains it best...

A conventional music CD has an electronic table of contents at the beginning of each disc. But a PC-recorded CD has several tables, with a new one written every time a new recording session adds something to the disc. Each of these tables points back to the previous one.

Personal computer CD drives read the last, most recent table first and work back through the series of indices - but audio CD players read only the first table.

A CD containing a copy-prevention system indexes the music correctly in the first table but then adds dummy tables containing deliberate errors. So CD players that read only the first table will play the music normally. But PC CD drives - which people use for copying - look at the last table, see garbage, get confused and play or record nothing.

Unfortunately, some audio CD players and in-car players use PC CD drives, and will not legitimately play a protected CD you have paid for. Nor can people play music CDs on their PCs.

BMG claims that the "Red Book" standard (the one that needs to be followed else you can't have the "Audio Compact Disc" label on your CD allows for this copyprotection in that the standard says "read the first index first" and that technically PC CD-Drives aren't following the standard.

Of course, a quick software upgrade from your local CD-drive website and voila... problem solved.