LCD stuck on unusable refresh rate under FreeBSD 6.0

[Rools S]

I am new to FreeBSD and installed the 6.0-RELEASE on an AMD64 with a Nvidia
GeForce 6600 GT graphics card and
a Samsung SyncMaster 930BF 19" TFT.

My problem is that the vertical refresh rate seems stuck at 60Hz and the
horizontal sync rate at 63.8kHz.
This causes serious eye strain and I can't use the system for very long
before I get a headache.

The optimal settings for this monitor is 1280x1024 with hor. 80kHz and vert.
75Hz which I can get when I plug
it into a win2k box and load the Samsung drivers.

I am using the open-source nv drivers for the gpu.(can't find nvidia
proprietary that support 6.0-RELEASE on AMD64)

My X-server setup works fine but the xorg.conf configurations don't have an
impact on the refresh and sync rates.

I have tried the following settings in xorg.conf:
-----------------------------------------------------------------------------------------------------

Section "Monitor"
Identifier "Monitor0"
VendorName "SAM"
ModelName "SyncMaster"
HorizSync 80-81
VertRefresh 75-75
EndSection

Section "Modes"
Identifier "1280x1024"
ModeLine "1280x1024" 135.00 1280 1296 1440 1688 1024 1025 1028 1066 +hsync
+vsync
EndSection
-----------------------------------------------------------------------------------------------------

I've also tried without the "Modes" section and HorizSync values of 30-81
and VertRefresh values of 56-75
when I
Xorg -config xorg.conf.new
X works fine and but the OSD still shows the HorizSync to be 63.8 and
VertRefresh 60
(on the windows box the OSD displayed the correct rates after driver setup)

my /var/log/Xorg.0.log has the following lines of output:

(--) NV(0): Virtual size is 1280x1024 (pitch 1280)
(**) NV(0): *Default mode "1280x1024": 135.0 MHx, 80.0 kHz, 75.0 Hz
(II) NV(0): Modeline "1280x1024" 135.00 1280 1296 1440 1688 1024 1025 1028
1066 +hsync +vsync

there is also a section in the log:

(II) NV(0): Supported VESA Video Modes:
..
(II) NV(0): 1280x1025 at 75Hz
..

My "screen" configuration in the xorg.conf file is as follows:

Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 24
Modes "1280x1024"
EndSubSection
EndSection

I would greatly appreciate it if someone can point me in the right direction
on this since with the current
settings my system is unusable to me.

Cornelis