When I was first testing with cgminer, it would fluctuate because I had AMD overdrive enabled so I could move the power control slider to +20% like everyone was saying to do. Now I have that disabled and don't need that silly slider anymore. I just ran another test with cgminer and I can set the clock to what I want and it stays there. Are you saying you don't install "catalyst control center"? Hmmm maybe that's the real problem. Just tried installing driver without it and it didn't work.