Resolution (dpi) correctly deteced by X11 but then not used

Hi,

I have X11 configured to correctly determine the DPI of my monitor:

[0] nokile:/var/log# grep DPI Xorg.0.log
(**) RADEON(0): DPI set to (127, 145)
[0] nokile:/var/log#

but apparently some other program messes with this setting, because as soon as the GUI is running:

[0] nokile:/var/log# xdpyinfo | grep reso
  resolution: 96x96 dots per inch
[0] nokile:/var/log#

I have already changed the DPI in gconf under desktop -> gnome -> font_rendendering but the problem persists.

Does anyone know how I can reset the dpi to the correct value or which program is responsible for messing it up?

Thanks in advance,
-Nikolaus