dual screen troubles

[baman]

Hi all
I have some issues with getting a good dual-screen configuration,
it's not easy for me to find where the problems orginate, so I don't
know where to ask for help really.
I hope someone here can help point me in the right direction or so

I have a ATI Radeon HD 4350 with one DVI and one HDMI connection.
I have hooked up a 1680x1050 lcd monitor on the DVI cable and a Sony 1920?1080 TV on
the HDMI connection.

I get video on both and I can configure them to multi-screen.
But now the problem starts.

Using ATI's propretary drivers mostly work ok except that
i cannot figure out how to have it utilize the whole display of the TV.
The monitor is correct, but on the TV there is only a 1680x1050 square with a new screen inside
the full 1920?1080 resolution, so there is like a 5 centimeter black border around the screen.
This is what i get by enabling "single display desktop (multi desktop)" in ati ccc.

Anyone familiar with that?

And second, using the foss "radeonhd" drivers, both tv & montior gets their correct resolutions.
(so i guess its a ati driver bug?)

But the reason i just cant use "radeonhd" drivers is because of another problem.
Using those drivers, my monitor shows display corruption (out of sync settings or something).
I can configure the monitor to a lower resolution and the display gets stable, but
i'd like to use it at its native resolution.

In fact the monitor only works properly with native resolution and the ati drivers.
Can there be bug in radeonhd dvi / edid code?

So I'm asking if anyone have some suggestions how i could proceed
into contacting the right people or debugging/configuring away these issues.

Thanks in advance!

[conholster]

On windows 7 atleast you have to adjust the underscan overscan slider. Think I did this on Ubuntu as well. Not sure I got it working though. If I remember correctly the problem comes from the TV manufacturers always make the picture smaller, cause some dvd players make the picture bigger than 1080p. Also make sure the input from your computer is configured as PC input. Usually in the TV settings.

[baman]

conholster: thanks for the explanation!
i poked around with some settings on the tv and finally i found one that was causing the black borders! so it wasnt a driver issue at all.

i'll repost the foss-related problems in the other forum after i try some more