请教显示器驱动问题

显示器是三星710n，但是目前Ubuntu8.04系统未认出来，显示为未知，若改成即插即用则刷新率上限只有55，修改xorg不成功无法进入图形系统，具体的xorg修改内容如下，请问有什么问题吗
Section "Monitor"

Identifier "Samsung 710N"

HorizSync 30-81

VertRefresh 56-75

Option "DPMS"

EndSection

Section "Screen"

Identifier "Default Screen"

Device "Geforce2 7300gs"

Monitor "Samsung 710N"

DefaultDepth 24

SubSection "Display"

Depth 1

Modes "1280×1024" "1024×768" "800×600" "640×480"

EndSubSection

SubSection "Display"

Depth 4

Modes "1280×1024" "1024×768" "800×600" "640×480"

EndSubSection

SubSection "Display"

Depth 8

Modes "1280×1024" "1024×768" "800×600" "640×480"

EndSubSection

SubSection "Display"

Depth 15

Modes "1280×1024" "1024×768" "800×600" "640×480"

EndSubSection

SubSection "Display"

Depth 16

Modes "1280×1024" "1024×768" "800×600" "640×480"

EndSubSection

SubSection "Display"

Depth 24

Modes "1280×1024" "1024×768" "800×600" "640×480"

EndSubSection

EndSection