Thanks, XXXXX XXXXX do see you have a subscription service of some sort so just rate my answer when satisfied and everything should be handled appropriately by JustAnswer on their end.
You're probably trying to play this file in Quicktime and, unfortunately, it has limited support for many common codecs.
Instead, you may wish to try using MPlayerX. It is a free, Lion compatible, multimedia player available from the Mac App Store (if available in your country) or directly from the following website:http://mplayerx.org
Alternatively, if you wish to continue using Quicktime you could install Perian. This is a codec that extends the compatibility of Quicktime to include many of the formats supported my MPlayerX. Note, it is discontinued but works fine under Lion:http://perian.org
(Note: You'll need to scroll down the page to find the download link).
Hopefully, this info will answer your question. If you continue to have questions on this topic, just reply back to this discussion. I will be more than happy to work with you further.
Thanks and good luck,
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, so please reply to me if there is anything else I can do to help before choosing those options. I appreciate your patience on this matter.