I've completely given up setting up the refresh rate with an ATI card through CCC or any other tool in Linux. It won't work (good job ATI). My best tip for you is to google search your monitor model, find the correct specifications for vertical and horizontal refresh rate and set them up manually at your /etc/X11/xorg.conf
Here is an example of mine:
Identifier "Generic Monitor"
That keeps my monitor at 75Hz all the time, but the same values may not apply to yours. Again, google search for you monitor (if you don't know the number or don't have the manual), backup and edit that file manually.