Movies that I have downloaded look fine but when played have no sound. Is this a gimmick for people who download to become discouraged and not to download further (this has happened several times) or is there a fix for this problem? Many times the option to purchase Multichannel Plug-in – Dolby® Digital 5.1 appears. The website says "With digital multichannel sound you can enjoy revolutionary sound quality in the comfort of your own home". Would this solve the problem? Are these two connected or not?