I've had this problem before. I can't remember the exact cause, but I would recommend uninstalling your amd drivers and installing fresh copy. I'll think about it and get back to you if i come up with anything.

edit: uninstall and delete your MSI afterburner, download/install the latest beta. Then google "msi unsupported overclock" to get the eula agreement to copy paste into cfg file. Set overclocking mode to 2. see if that helps