Dell Dimension 7100 XPS ATI Raedon 5770 HD driver issue

Hi there... I have got a little problem here with my dell dimension. The current driver installed is the one provided by dell... Problem is:

I have a hdmi cable leading to a tv where I can see my series on a much bigger monitor. But the signal cannot be watched in full monitor size (which is 46") ... there is always a black bar between the screen and the physical end of the tv screen... I cannot change that by adjusting the screen over the tv options. Else I didn't find any options on my PC concering graphic card options or in the CataclysmControlCenter (CCC).

I had another driver from the AMD homepage (the newest one for the hd 5700 series) where I could watch in fullscreen. The Problem with this one was that I had often issues with wrong illustrations on the windows 7 screen (remembered me a bit of a broken graphics card like fizzle stuff) where there were serious problems in the taskbar or in the bar of my browser / explorers ...

anyone can help me out with that?

Data:

My PC has:

AMD Phenom X6 1045T (six CPU @2,70 GHz) CPU

ATI Raedon 5770 HD graphic card

8 GB DDR3 Ram

1,5 TB SATA (@7200 rpm)

and was bought in february 2011

Cheers,

hubie