Go to your desltop and open up your Video card control panel. go to your vsync option and turn it to On, Application Controlled or On unless Application Specifies (either depending on what driver version or type AMD or NVidia) Then go in game at main menu and change your vsync options from there. Keep in mind you may experience a 50/50 chance of crashing when changing the options if your using an ATi/AMD card. The setting swill save if you crash jsut double check them and see if its on, do not use SMART if you are using an ATi/AMD card. it will revert to OFF.
Hope that helps
There an issue with the NVIDIA driver that apparently has a hard-coded Rage profile with vsync set to 'forced off', I had this, and manually adding a profile for Rage.exe and just making it use the global setting (which I've set to use whatever the application wants) made everything work for me. See http://forums.steampowered.com/forums/showpost.php?p=25609346&postcount=5