So today none of the embedded Youtubes in Realcent would not work in Safari. So after a few Googles this fixes it. I hope it helps some one else.
EricJohnson68
Re: Safari suddenly stopped playing embedded YouTube videos
Jun 23, 2010 11:48 PM (in response to goChickenboy)
I've gone through the fixes here, with no luck. But then I went to Safari->preferences, Security tab, "show cookies" button. I typed youtube into the search, selected them all, and removed them. The embedded videos worked right away. I accept all cookies, also. Hope that helps someone else!
Mac OS X (10.5.8)