Firstly, I'd recommend that you update your SX20 from TC7.1.4 to a more recent version (ie TC7.3.3) to address some of the security vulnerabilities in the older versions (here's one example: Cisco SA 20150320-OpenSSL). There have been a number of improvements to the way the presentation is handled (and the automatic starting of presentation after a disconnect) in the later versions too.
Note: If the above hasn't answered your question, I'd suggest you move your thread to the TelePresence section of the forums where these devices are more actively discussed than in the Unified Communications Applications section you have posted in.
Wayne
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Wayne
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