Ps3 Hook Up Problem on a 42" Samsung Lcd Tv?

When I try to connect my PS3 to my one Samsung LCD tv with the HDMI I get a message on the tv screen that says "NOT SUPPORTED". Anyone have any ideas why. I recall something like this when I set the PS3 up on my other Samsung but now I forget what I did. Any help would be deeply appreciated.

Suggestion:

Try holding the power button on the Ps3 while it's turned off. Hold it until you hear the second beep. The first beep is it turning on. After the second beep the display settings are reset and you should be able to set it up for HDMI