Hey, I have a late 2011 15" Macbook Pro and I'm having some multiple displays issues. I use an HDMI to displayport adapter to hook my macbook up to my HD TV and it has been working great in the past but today it is not. I know the macbook is detecting the TV because both screens turn blue when I plug in the cord, system properties pops up on both screens, music plays through the TV speakers, and mirroring displays works fine. I can't move my mouse over to the TV display. As you can see, when mirroring the displays I can see the blue monitor boxes just fine but when I try multiple displays the boxes disappear and my mouse can only access my macbook's screen. I tried restarting and fixing permissions, but there was no difference. Right now I'm thinking it might be the adapter that's broken, but I'd like some more input before I buy another one. Thanks for any input in advance.