1) Do you get the same behavior if you attach your laptop to a different TV?
OR
Do other computers attached via HDMI to your TV display this behavior?
3) Have you tried a different HDMI cable?
4) What resolution and refresh rate have you configured for the TV? Does changing these parameters change behavior?
5) What video driver version are you running?
@tehhunter encountered a similar issue in
http://rog.asus.com/forum/showthread.php?10255-G74SX-NH71-HDMI-Output-Problems It turned out to be his TV.
G74SX-A1 - stock hardware - BIOS 202 - 2nd Monitor VISIO VF551XVT