Converter box

I just bought a Toshiba C655D-5087 which is a good deal for the $350 I paid. Basically my desktop was giving me problems and I needed a more reliable computer for work. My old computer used to have a Geforce 5950 Ultra graphics card and when hooked up to my Toshiba 42" via DVI (PC) to HDMI (TV) it was fine. That card finally died on me and I ended up replacing it with a Geforce 6200. I used the same connection and again everything was fine.

Now with this laptop using the onboard ATI 4200 HD, I am having problems with displaying it on my TV. At first I had a VGA to DVI adapter and then from there used the DVI to HDMI cable I had been using and it wouldn't work. After a bit of research I determined that I was basically trying to input a digital signal from an analog signal with just an adapter. Needless to say this wasn't working.

I finally decided to purchase a analog to digital converter box. Namely, the one that can be found here.

It basically takes either a VGA + 3.5mm audio or component and outputs into an hdmi. So I get it today and set it up and I can't get the tv to show fullscreen. It has two vertical black bars on the sides. It lookes like it is set at 4:3 instead of 16:9. I have gone into the Control Center for the ATI and I just can't figure out what to change. I've called the converter people and they said that they haven't had that problem. I called the ATI people and they said they don't know what to do because I am using the converter (a lazy excuse it would seem).

Also, when I use just the VGA to VGA directly to the computer it is fine. Albeit, I don't get the audio unless I plug in the jack and definitely can't get the HD that way either.

So what should I do to fix this? I have tried many resolution combinations and none seem to get it right. Additionally, even when the tv is showing the output, it doesn't have that HD look to it (text is not crystal clear). Please help!!!