I purchased another computer from Apple, another MacBook Pro. I down-loaded the apps from Creative Cloud (PP 6.02, Media Encoder, etc.) I down-loaded the "fix" for Media Encoder. I have a portable media drive that I can switch. On the older computer, it plays just fine. On the NEW computer, about a third of the stuff is off-line. I investigated, and all the off-line stuff was originally encoded with Final Cut Pro 7.03. It says on page 43 of Adobe Premiere Pro CS6 Classroom in a Book that "it's best to use Final Cut Pro to import your media." I tried to reconnect it, but the error messege says "codec missing or unavailable." Help!
You are most welcome, and glad that it helped. I think that your question has been answered. Take a look at this article for marking a thread as Answered: http://forums.adobe.com/thread/1058744?tstart=0