First of all, what kind of content from lynda.com do you have? Downloadable files? Files on CDs/DVDs? Stream recordings?

DRM protected Windows Media files can easily be detected on Windows by watching their file properties. You should be able to check your mov files on a Mac in a similar way.

Can you play your MOV files with QuickTime 6? Is QuickTime 7 required to play your MOV files? The latest MOV files are different 'coz they use H.264 video codec. Older software may crash because of this.