Specifically, The following behavior is observed on monitors that report TV compatible timing of 59.94Hz but not 60Hz.
The refresh rate in Windows 7 does not apply the user selected settings
Updated 12/21/2009 02:26 PM
Screen refresh rate in Windows 7 does not apply the user selected settings on monitors & TVs (that report specific TV compatible timings)
Please see the following article if you have issues with a computer that is running Windows 7, you cannot change the screen refresh rate for certain monitors.