shaky picture when connecting my philips hdtv via dvi to my geforce 5200

I'm not 100% sure on the termonology to use but, I have a geforce 5200 that connects via dvi to my philips 55" hdtv using 1080i display. The problem is that my picture on the tv is shaky. I have the resolution set to 1920 X 1080 with the refreh set at 60mhz.

If I drop the resolution down to 800X600 everything is clear but I can only see 1/4 the desktop.

Another problem regardless of the resolution used is, the output looks really bad, horrible colors and unreadable text.

What can I do via settings or connectors ... any help at all is greatly appreciated, because I'm lost on all of this.

thanks