Refresh rate on Samsung SyncMaster 932B

[agds]

The user's manual recommends setting a refresh rate no higher than 60Hz, but I seem to be stuck at 75. Here are the relevant sections of my xorg.conf:

Section "Monitor"
        Identifier      "Samsung SyncMaster 932B"
        Option          "DPMS"
        HorizSync       60-65
        VertRefresh     50-60
EndSection

Section "Screen"
        Identifier      "Default Screen"
        Device          "nVidia Corporation NV17 [GeForce4 MX 420]"
        Monitor         "Samsung SyncMaster 932B"
        DefaultDepth    24

        SubSection "Display"
                Depth           24
                Modes           "1280x1024" "1152x864" "1024x768" "800x600" "640
x480"
        EndSubSection
EndSection

Here's the output of xrandr:

 SZ:    Pixels          Physical       Refresh
*0   1280 x 1024   ( 339mm x 271mm )  *75  
 1   1152 x 864    ( 339mm x 271mm )   75  
 2   1024 x 768    ( 339mm x 271mm )   75  
 3    800 x 600    ( 339mm x 271mm )   75  
 4    640 x 480    ( 339mm x 271mm )   75  
Current rotation - normal
Current reflection - none
Rotations possible - normal 
Reflections possible - none

Notice that the only refresh rate option is 75Hz.

After I did dpkg-reconfigure xserver-xorg, the horizontal sync was set to 30-65 and the vertical refresh to 50-75. I manually edited the range in the hopes it would force the desired refresh rate. Is there some reason X would be ignoring the ranges I've set?

[agds]

Okay, I found a solution. I downloaded a GTF modeline generator and got the appropriate modeline for 1280 x 1024 @ 60 Hz. For anyone else trying this method, note that you should probably add

#include <string.h>

to the code to avoid warnings related to the strcmp library function. So my xorg.conf now looks like this:

# /etc/X11/xorg.conf (xorg X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the /etc/X11/xorg.conf manual page.
# (Type "man /etc/X11/xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
#   sudo dpkg-reconfigure -phigh xserver-xorg

Section "Files"
        FontPath        "/usr/share/fonts/X11/misc"
        FontPath        "/usr/X11R6/lib/X11/fonts/misc"
        FontPath        "/usr/share/fonts/X11/cyrillic"
        FontPath        "/usr/X11R6/lib/X11/fonts/cyrillic"
        FontPath        "/usr/share/fonts/X11/100dpi/:unscaled"
        FontPath        "/usr/X11R6/lib/X11/fonts/100dpi/:unscaled"
        FontPath        "/usr/share/fonts/X11/75dpi/:unscaled"
        FontPath        "/usr/X11R6/lib/X11/fonts/75dpi/:unscaled"
        FontPath        "/usr/share/fonts/X11/Type1"
        FontPath        "/usr/X11R6/lib/X11/fonts/Type1"
        FontPath        "/usr/share/fonts/X11/100dpi"
        FontPath        "/usr/X11R6/lib/X11/fonts/100dpi"
        FontPath        "/usr/share/fonts/X11/75dpi"
        FontPath        "/usr/X11R6/lib/X11/fonts/75dpi"
        # path to defoma fonts
        FontPath        "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
EndSection

Section "Module"
        Load    "bitmap"
        Load    "ddc"
        Load    "extmod"
        Load    "freetype"
        Load    "glx"
        Load    "int10"
        Load    "vbe"
EndSection

Section "InputDevice"
        Identifier      "Generic Keyboard"
        Driver          "kbd"
        Option          "CoreKeyboard"
        Option          "XkbRules"      "xorg"
        Option          "XkbModel"      "pc104"
        Option          "XkbLayout"     "us"
EndSection

Section "InputDevice"
        Identifier      "Configured Mouse"
        Driver          "mouse"
        Option          "CorePointer"
        Option          "Device"                "/dev/input/mice"
        Option          "Protocol"              "ExplorerPS/2"
        Option          "Emulate3Buttons"       "true"
EndSection

Section "Device"
        Identifier      "nVidia Corporation NV17 [GeForce4 MX 420]"
        Driver          "nvidia"
        BusID           "PCI:1:0:0"
        Option          "UseFBDev"              "true"
EndSection

Section "Monitor"
        Identifier      "Samsung SyncMaster 932B"
        Option          "DPMS"
        HorizSync       30-81
        VertRefresh     56-75
        # 1280x1024 @ 60.00 Hz (GTF) hsync: 63.30 kHz; pclk: 108.88 MHz
        Modeline "1280x1024_60.00"  108.88  1280 1360 1496 1712  1024 1025 1028 
1060  -Hsync +Vsync
EndSection

Section "Screen"
        Identifier      "Default Screen"
        Device          "nVidia Corporation NV17 [GeForce4 MX 420]"
        Monitor         "Samsung SyncMaster 932B"
        DefaultDepth    24
        SubSection "Display"
                Depth           1
                Modes           "1280x1024_60.00" "1152x864" "1024x768" "832x624
" "800x600" "720x400" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           4
                Modes           "1280x1024_60.00" "1152x864" "1024x768" "832x624
" "800x600" "720x400" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           8
                Modes           "1280x1024_60.00" "1152x864" "1024x768" "832x624
" "800x600" "720x400" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           15
                Modes           "1280x1024_60.00" "1152x864" "1024x768" "832x624
" "800x600" "720x400" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           16
                Modes           "1280x1024_60.00" "1152x864" "1024x768" "832x624
" "800x600" "720x400" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           24
                Modes           "1280x1024_60.00" "1152x864" "1024x768" "832x624
" "800x600" "720x400" "640x480"
        EndSubSection
EndSection

Section "ServerLayout"
        Identifier      "Default Layout"
        Screen          "Default Screen"
        InputDevice     "Generic Keyboard"
        InputDevice     "Configured Mouse"
EndSection

Section "DRI"
        Mode    0666
EndSection

Hopefully someone will find this useful.