HDTV widescreen - Grey bars on side, not black?


I have a small (23") Sony Bravia HDTV and the bars on the side for regular 4:3 television are bright gray, not black. It's driving me crazy. I've been on the phone with Sony and they don't know if it's possible to change the bars to black, but the salesman and J&R World says there is but he doesn't know how. My cable company says it's a TV issue and Sony says it's a cable issue.

This particular TV has been discontinued so I can't find it in a store to ask a salesman.

Anybody have an idea?
kublakhan
Thanks for all the responses - i've checked all the settings many times on my own and with Sony tech support on the phone but there's no setting for the bars to be found.

Thanks Swamp, I posted the question on the av forum you suggested.
The gray bars are better for preventing burn-in but is really only important for plasma TVs.
Rwwear"The gray bars are better for preventing burn-in but is really only important for plasma TVs."
Where did this information come from?Link?
Well it is also true for CRTs but since we were discussing an LCD I didn't include CRTs. LCD TVs are not succeptable to burn in. They are but very slightly. I don't have a source. It is pretty common knowledge though. Okay here are some sources. http://www.lcdtvbuyingguide.com/lcdtv-plasmavslcd.shtml www.flattvpeople.com/tutorials/lcd-vs-plasma.asp www.audioholics.com/techtips/specsformats/displays_LCD_vs_Plasma3.html

You'll have to read for yourselves to find the info.
What model TV and how is it connected? Where the bars are introduced may depend upon how the signal is being transmitted from the source. For example, there is SD material occasionally transmitted on HD channels, where the black bars are "supplied" by the broadcaster. For some formats, I believe it may be generated by the CATV box. In other cases, it is generated by the TV...

But, if you can't find a control for changing the bars on either your TV or the CATV box, sounds like it is pointless anyway...