Mini DisplayPort to HDMI Adapter Not Working

I just got a mini displayport to hdmi adapter that I ordered from dealextreme and it does not work. The adapter had very good reviews and not one review said it didnt work. When I plug in the adapter (with or without a hdmi cable attatched to it) to my macbook, the screen blinks and then goes back to normal. When everything is properly connected the tv shows no input signal (I am on the correct input channel) and the screen doesnt appear in the displayas settings in my macbook pro. I tried to reboot the macbook, shut down and turn on the screen and nothing seemed to work. The detect display option in the system preferences didnt help. I appreciate any help I can get.

-Yonatan