I'd been having troubles with my new TV. So, I went to the manufacturer's website, found a support email address, and sent an email describing my problem – basically, I was getting 2 seconds of blue screen when switching from an HD channel to non-HD. About 20 minutes later, I recieved an email:

Hi Fred,

Please force your HD and SD channels to the same output resolution.
Thank you for contacting Syntax Technical Support.

Joe P

Now that's great customer support. I got a personalized email with specifc instructions on how to fix my problem in 20 minutes.