I got the same problem and its other website also.. i been hearing some crap about mp4 and some codecs for play back because of some plug it related with Chrome also and some license issues, im not sure, i got the same problem in linus also using Opera, its not just a MAC os problem! i love Opera, causes it uses less ram and its fast and blocks all the ads and etc etc but it sucks i need to open Chrome to play videos or watch movies you know... only ting that works with opera in you tube, all other videos do not load at all... PLease help!