Well, the gpu looks ok. That's not too hot. Try SpeedFan and post the temps of your cpu.
http://www.almico.com/sfdownload.php
Also, what is the make, model, and wattage of your power supply?
How is your tv connected to your computer? And what resolution is it displaying at? Maybe turning down the TV rez might boost performance.
Also, you said that your cpu usage was at 40% while on the web and watching the dvd, but does it spike when you load a new page?