Laptop to TV flicker

I like to occasionally plug my laptop ? via an HDMI cable ? to my television. Usually, for the first show I stream, the picture is fine, but afterwards, the picture flickers incessantly. I?ve tried adjusting the cable to see if it isn?t properly seated on both ends ? despite not moving it. I?ve tried clearing the cache. I?ve tried restarting the computer. Once or twice, I?ve uninstalled and reinstalled Flash. Finally, I switch to some other entertainment choice. Any ideas as to the flicker and how to fix it? Thanks for your ideas!