Actually I just found something that might help you.I totally forgot you have to edit some settings in the MSI Afterburner file.
Yea make sure you open up Catalyst Control Center, go to ATI Overdrive, and first unlock the card and second disable (uncheck) the ATI Overdrive box. Secondly, in MSI Afterburner, make sure you change the config file where it says "allow unofficialoverclocking =" from 0 to 1. Then you should be good to go.
Tell me if that works for you