The CDS_RESET flag of the ChangeDisplaySettingsEx function does not work as expected in Windows Vista or in Windows Server 2008
You use the ChangeDisplaySettingsEx function together with the CDS_RESET flag to reinitialize the graphics adapter on a computer that runs Windows Vista or Windows Server 2008. However, if the requested settings are the same as the current settings of the display adapter, the system does not trigger an activation of the video present network (VidPN) on the display adapter. Therefore, the graphics adapter is not fully reinitialized.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB959662.