Tiens, je te file la section "Monitor" de mon XF86Config, sachant que j'ai justement un IIayama Vision Master Pro410, que j'utilise en 1280x1024 @85Hz.
 
Section "Monitor"
 
    Identifier  "My Monitor"
 
# HorizSync is in kHz unless units are specified.
# HorizSync may be a comma separated list of discrete values, or a
# comma separated list of ranges of values.
# NOTE: THE VALUES HERE ARE EXAMPLES ONLY.  REFER TO YOUR MONITOR'S
# USER MANUAL FOR THE CORRECT NUMBERS.
 
    HorizSync   27-96
    VertRefresh 50-160
 
EndSection