Digital Rights Management (DRM) is causing your problem. The songs that
won't play are protected with DRM, which will not allow you to insert
them into PowerPoint. The technology thinks you are trying to distribute
these files in evil, nefarious ways. It might be right; it might be
wrong. But it doesn't care; it just won't let you do it.
--David
--
David M. Marcovitz
Microsoft PowerPoint MVP
Director of Graduate Programs in Educational Technology
Loyola College in Maryland
Author of _Powerful PowerPoint for Educators_
http://www.loyola.edu/education/PowerfulPowerPoint/