Using Macbook Pro mid-2010 with HDMI

I'm posting this because I couldn't find good tips on the forums regarding this topic. So, here ya go folks. I was trying to connect my mid-2010 macbook pro to a Samsung TV LCD that displays at 1080p. I bought the Apple display port--HDMI adaptor, and was all excited as the new macbook pros allow for audio plus display with this adaptor.
So I plugged it in to my HDMI cable and thought that would be it. Nope.
So, here's the trick: in system preferences go to "display" then go to "arrangement" and there uncheck the "mirror" option. Then, in display, either click on "detect display" or click on the 1080p option from the list. That's it...it worked great!