I have a laptop with an HDMI output port running Vista, and an HDTV with HDMI input ports. The laptop is set to extend its desktop onto a second monitor. When I connect the computer to the TV with an HDMI cable, my laptop screen usually flickers rapidly. Most of the time it lasts for about 30 seconds, but sometimes it lasts for several minutes and once in a while it doesn't happen at all. It wouldn't be so bad except that the cursor moves back to the center of the laptop screen with each flicker, so I can't really do anything until the machine decides it's ready to calm down.

I haven't been able to find any pattern at all for the causes or duration of the flickering. It doesn't seem to matter what programs the laptop is running when I connect it to the TV, whether I enable the extended display before or after I connect the TV or which HDMI port/cable I use. What could be causing this, and how can I make it go away?