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I am using Ubuntu 14.04. With Skype Linux version 188.8.131.52 when I try a conference call, my friends can hear me, but there is no video. They receive a notification saying I need to upgrade Skype. There is no problem for a simple video call. Both audio and video work perfectly. I have downloaded Skype from http://www.skype.com/. The Skype website don't have any recent updates for Linux distributions.
Any help on how to solve this?