I found the only NETBOOK that worked well at this were the ION DRIVE models. The cause is the netbook and the cure is a more capable machine.
I have encountered folk that don't believe it.
When I hook up my Netbook to my HDTV using a VGA to VGA cable, all seems to be well. I use only my HDTV as the monitor for higher resolution. When I change the channel or input and go back to VGA, the TV becomes very jittery unless to mouse is off the screen (all the way to the right) or there's action going on (watching a movie).