HDMI output cropped edited

[pernel]

I recently prepared a Giada box with nvidia ION graphics with Mageia 3. When I try output to a HDMI TV the desktop becomes cropped so that the top and bottom panels in GNOME-classic becomes cropped away. Same phenomenon in KDE where the panel is partially cropped. How do I edit parameters so that this does not happen? The graphics configuration tool in Mageia does not give me any option to adjust parameters such as overscan.
EDITED: I played around more with the drakconf "configure graphical server" . In fact whatever settings I select give the same result: A somewhat cropped desktop without access to any of the panels. It does not seem the drakconf / configure graphics server changes anything at all!
Any help would be very much appreciated.

[pernel]

Found out the gnome-control-center allows me to set a correct screen resolution. Just wonder why dracconf "configure graphical server" does not work. Is this a bug?