someone told me that you shouldn't watch a TV program on a Plasma TV unless it comes in widescreen format. Is this true.

Thanks

If you are talking about damage to the unit by watching a cropped format program, that wouldn't be an issue. It would be like a regular tv watching a wide screen program, you'll just see the middle and not the edges, but in reverse.

You can watch anything on a Plasma TV, but depending on the definition of the TV, you will not be getting the best picture if the feed or signal you are getting is not as high a quality as the TV itself.

Here is a Plasma TV Faq Site (there is also advertising on the site also, but the information looked quite viable).