thank you for the wonderful screenshot.
as you can see, SetDisplayFrequency only allows you to set refresh rates that are available in windows. Please check your display properties, what frequencies are available for your graphics card / monitor combination.
LCD Displays often only allow 60 Hz refresh rate.
SetDisplayFrequency is most useful with CRT Monitors and CRT Beamers. LCD/DLP Beamers usually need more precise timings (e.g., 48Hz for NTSC movies, 50Hz PAL, 60Hz NTSC Video)
For advanced settings (people using LCD/DLP Beamers) you can use Power Strip from entech. It can be controlled from AnyDVD as well.
How to use PowerStrip is beyond the scope of AnyDVD's online help and my knowledge as well...