Basically, I had lots of issues with picture on the TV and no sound, and then vice versa on the laptop. I have a Dell Studio 15 laptop with HDMI output and a Panny 32LZD85 LCD TV, but I'm sure the instructions below will apply to all laptop to TV connections via HDMI.
Don't know if anyone still needs help with this but I've just recently overcome this problem after lengthy discussions with Dell support.
