1. Uninstall all AMD software expressly trough control panel
2. Reboot
3. Use driver sweeper (can be downloaded from guru3d)
4. Reboot
5. Download and install AMD SDK 2.6
6. Reboot
7. Download and install amd 13.4 driver
8. Reboot Cheesy

Price per kWh      |      USD $0.11 day, $0.02 night
Current as @       |      SEP 2013
Provider              |      EPS  
State/Province     |      Belgrade
Country              |       Serbia        

Add --gpu-engine xxxx   (xxxx being GPU MHZ)  to cgminer so it can constantly use that frequency. Mine also varied a lot in gpu utilization but after adding that line it worked great.

For no reason, it just stopped working today. I spent 4 hours figuring out how to make it work again...
This is the combination that worked for me

1. Uninstall all AMD software expressly trough control panel
2. Reboot
3. Use driver sweeper (can be downloaded from guru3d)
4. Reboot
5. Download and install AMD SDK 2.6
6. Reboot
7. Download and install amd 13.4 driver
8. Reboot

It should work now...