I did some experiments.
X_MODE_0 = 1440x900 106.47 1440 1520 1672 1904 900 901 904 932
It work well on fc5 and fc6 with Samsung 920NW and 940NW wide monitors.
Also with old client hardware (compaq SFF P3)
Do not use any other horzsync or vertrefresh rows not in header or in
exact ws section.