Dual display with xrandr doesn't seem to work in intrepid

Hi,

Since I have upgraded to intrepid the usual command I was using for dual display:

   xrandr --output VGA --mode 1280x1024 --right-of LVDS

doesn't give the correct display. Indeed, on my second screen I miss approximatively 200px on the right part of the screen. Does anybody know if it's a bug or if I need to change something in my configuration?

Thanks,
  François

I have x11-server-utils version 7.3+5

francois@dell:~$ lspci | grep Graphics
00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 0c)
00:02.1 Display controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 0c)

francois@dell:~$ xrandr --version
Server reports RandR version 1.2