I have a new Roku Express, only a few weeks old. When I first turn on the TV to watch something on the Roku, it does not show the screensaver, only a blank screen. It does not respond to the remote (and I know the remote signal is working because the light on the Roku blinks). The only way I can get it to work is by unplugging the HDMI cable from the Roku and plugging it back in. Then I can see the screensaver and everything works normally from there. But something obviously isn't working right, and I don't want to have to fiddle with the HDMI cable every time I want to watch something. How can I fix this?