have you tried using that monitor with a PC/Mac and testing similar refresh rates? That would take the 'amiga' variable out of the equation (I suspect it's the monitor that doesnt' like the rates anyway, given that the amiga + a cybergraphx card can generate far more screenmodes than most monitors would be happy with)..
If you can't get similar screenmodes working with a PC, then your monitor is at fault, of course and it's not the amiga causing you grief....
kevin orme
amiga university
www.amigau.com