Interesting. Have you tried renaming and then using a video player like vlc? Vlc for the Mac/PC can play just about anything. If that still doesn't work I'm at a loss my friend. I've never been successful with editing a unviewable file before.
One other thing. Have you tried other extensions? For instance .3gp or .avi? I'm not sure what format cm10 natively records, but I'd try that as well before giving up.
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