I have upgraded Skype dated 1 March 2013 6.3.59.582. Cannot get video. Anyone having this problem and solved? 21.5-inch iMac,3.1GHz Quad-core intel Core 17, Turbo Boost up to 3.9GHz,16GB 1600MHz DDR3 SDRAM-2x8GB,1TB Fusion Drive,NVIDIA GeForce GT 650M 512MB GDDR5