hm... what settings do you use to render? Whenever I make a fractal, I have my density on 4000, filter radius on 1, and oversample on 1 as well. Clean, noise-free results o.o
XD You could always try lowering your oversample. I used to have a lot of noise/blur in my fractals, and until I decided to fidget with the render settings, it just persisted XD Even today though, they get messed up for whatever reason (particularly after I reboot my pc) and I end up with suspiciously popular pieces, like my noise-fest bloom Radical. Give it a shot XD