新装的红旗5.0注定不能用1024*768???

以前装过4.0一切都好
这次搞个5.0的不能用1024*768
用这个分辩率一起动就黑屏
显示器三星743DF,显卡845GL
系统能认出显示器,显卡用的是810驱动
下面是我的xorg.conf内容
# XFree86 4.0 configuration generated by Xconfigurator

Section "ServerLayout"
Identifier "XFree86 Configured"
Screen 0 "Screen0" 0 0
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"
EndSection

# By default, Red Flag Linux 2.0 and later use fonts paths
Section "ServerFlags"
Option "AllowMouseOpenFail" "yes"
EndSection

Section "Files"
RgbPath "/usr/X11R6/lib/X11/rgb"
FontPath "/usr/X11R6/lib/X11/fonts/misc"
FontPath "/usr/X11R6/lib/X11/fonts/TrueType"
FontPath "unix/:7100"
EndSection

# This loads all the modules...


Section "Module"
Load "dbe"
Load "freetype"
Load "extmod"
Load "record"
Load "v4l"
Load "type1"
Load "dri"
Load "glx"
EndSection

Section "InputDevice"
Identifier "Keyboard0"
Driver "kbd"
Option "XkbLayout" "us"
EndSection

Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Device" "/dev/input/mice"
Option "ZAxisMapping" "4 5"
EndSection


Section "Monitor"
Identifier "S/M 743DF"
VendorName "Unknown"
ModelName "Unknown"
HorizSync 30-70
VertRefresh 50-160
#Modeline:3
Modeline "1024x768" 97.41 1024 1072 1192 1416 768 768 771 809
EndSection

Section "Device"
Identifier "Intel 845"
Driver "i810"
BoardName "Unknown"
EndSection

Section "Screen"
Identifier "Screen0"
Device "Intel 845"
Monitor "S/M 743DF"
DefaultDepth 24
Subsection "Display"
Depth 24
Virtual 1024 768
EndSubSection
EndSection

Section "DRI"
Group 0
Mode 0666
EndSection