System freeze with ATI card

Hi All.
My m/b (Intel G915EV) ships with an integrated video adapter.

(either KDE and Gnome) and I have to reboot.
Have you any idea?

Below you can see the xorg.cong automatically configured.

Thanks

Beppe


# Xorg configuration created by system-config-display

Section "ServerLayout"
       Identifier     "Default Layout"
       Screen      0  "Screen0" 0 0
       InputDevice    "Mouse0" "CorePointer"
       InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "Files"

# file minus the extension (like ".txt" or ".db").  There is normally
# no need to change the default.

# Multiple FontPath entries are allowed (they are concatenated together)
# By default, Red Hat 6.0 and later now use a font server independent of
# the X server to render fonts.

       RgbPath      "/usr/X11R6/lib/X11/rgb"
       FontPath     "unix/:7100"
EndSection

Section "Module"
       Load  "dbe"
       Load  "extmod"
       Load  "fbdevhw"
       Load  "glx"
       Load  "record"
       Load  "freetype"
       Load  "type1"
       Load  "dri"
EndSection

Section "InputDevice"
# Specify which keyboard LEDs can be user-controlled (eg, with xset(1))
#       Option  "Xleds"         "1 2 3"

# To disable the XKEYBOARD extension, uncomment XkbDisable.
#       Option  "XkbDisable"

# To customise the XKB settings to suit your keyboard, modify the
# lines below (which are the defaults).  For example, for a non-U.S.
# keyboard, you will probably want to use:
#       Option  "XkbModel"      "pc102"
# If you have a US Microsoft Natural keyboard, you can use:
#       Option  "XkbModel"      "microsoft"
#
# Then to change the language, change the Layout setting.
# For example, a german layout can be obtained with:
#       Option  "XkbLayout"     "de"
# or:
#       Option  "XkbLayout"     "de"
#       Option  "XkbVariant"    "nodeadkeys"
#
# If you'd like to switch the positions of your capslock and
# control keys, use:
#       Option  "XkbOptions"    "ctrl:swapcaps"
# Or if you just want both to be control, use:
#       Option  "XkbOptions"    "ctrl:nocaps"
#
       Identifier  "Keyboard0"
       Driver      "kbd"
       Option      "XkbModel" "pc105"
       Option      "XkbLayout" "us"
EndSection

Section "InputDevice"
       Identifier  "Mouse0"
       Driver      "mouse"
       Option      "Protocol" "IMPS/2"
       Option      "Device" "/dev/input/mice"
       Option      "ZAxisMapping" "4 5"
       Option      "Emulate3Buttons" "yes"
EndSection

Section "Monitor"
       Identifier   "Monitor0"
       VendorName   "Monitor Vendor"
       ModelName    "Unknown monitor"
       HorizSync    31.5 - 37.9
       VertRefresh  50.0 - 70.0
       Option      "dpms"
EndSection

Section "Device"
       Identifier  "Videocard0"
       Driver      "radeon"
       VendorName  "Videocard vendor"
       BoardName   "ATI Radeon X600"
EndSection

Section "Screen"
       Identifier "Screen0"
       Device     "Videocard0"
       Monitor    "Monitor0"
       DefaultDepth     16
       SubSection "Display"
               Viewport   0 0
               Depth     16
               Modes    "800x600" "640x480"
       EndSubSection
EndSection

Section "DRI"
       Group        0
       Mode         0666
EndSection