PC to TV via DVI no input

Hello,

I have tried many times to setup my PC to my TV (as a second monitor) via the DVI connection on my PC straight to a DVI (yes it is an older HDTV) but cannot get the PC to detect the TV as a device.

TV: Magnavox 42MF230A Plasma
PC: Dell Studio 540 w/ Nvidia GTS240 graphics card.

The card detects a second monitor with no problems, but will not recognize the TV.

Any help?

**More information - connection steps**

1. I ran the DVI-D to DVI-D cable from the second DVI connection on the GTS 240 to the DVI input connection on the TV.
2. Select DVI as the input source on the TV
3. Go through the Win7 "screen resolution" option and click "Detect"

No additional connection is detected.

I've tried all combinations of turning on and off the PC and TV to no avail as well.

In addition I used a DVI to VGA coverter and ran a VGA cable to the VGA input on the TV and while I did notice a green flash to the TV during the boot process of the PC, still no detection of the TV.

Resolution can be a factor as well, there are ways to force detection or force a resolution, but I can't help there.
I have a sharp TV with a top ATI card. It will not recognize my TV until I load catalyst control center, then catalyst sees it as a sharp. I have no Idea why ccc can see it and Windows won't. Another freaky thing when running vista, if the tv wasn't on during boot then I'd get no display at all. In Win 7 it doesn't matter.