Howto set my NEC LCD1850E to 60hz in XF86Config-4

[William Ballard <40414.nospam@comcast.net>]

I am googling stuff but I don't understand it.

I have ATI 9800XT with non-free drivers and NEC Multisync LCD1850E 
monitor.  fglrxconfig has generated XF86Config-4:

[snip]
Section "Monitor"
    Identifier  "Monitor0"
    HorizSync   31.5 - 80.5
    VertRefresh 60 - 75
    Option "DPMS"
[snip]
[bunch of commented out Modelines]
[snip]
Section "Screen"
    Identifier  "Screen0"
    Device      "ATI Graphics Adapter"
    Monitor     "Monitor0"
    DefaultDepth 24
    #Option "backingstore"
 
    Subsection "Display"
        Depth       24
        Modes       "1280x1024"
        ViewPort    0 0  # initial origin if mode is smaller than 
desktop
#        Virtual     1280 1024
    EndSubsection
EndSection
[snip]

My monitor is reporting H79.9 V74.9 1280x1024.
In Windows when I set it to 60hz it reports H64.0 V60.0 1280x1024,
which is the "natural" resolution.  How can I tell X to run it at 
"60hz"??

It is important to run at natural refresh rate for video (to prevent 
jerkiness).

Thanks.