try downloading and installing

Updated ati drivers
*reboot*
latest ATI SDK tools  <-- didn't work  
*reboot*
latest cgminer


still no luck?  try bfgminer < - -- Thought this was only for ASIC?

still not working, idiot-proof solution is BITMINTER.  <---- using out of desperation... 

Are you using CGminer for Linux or Windows?