While this fixes the artifacts, I can no longer enable compositing under kwin and trying to do so sometimes crashes X (aticonfig --set-pcs-str=DDX,ForceXAA,FALSE returns fglrx to the old behavior).
Anyway there is a bug report on ati.cchtml.com now.
i can confirm it too, artifacts are gone and the screen minimize delay is still gone with it
While this fixes the artifacts, I can no longer enable compositing under kwin and trying to do so sometimes crashes X (aticonfig --set-pcs-str=DDX,ForceXAA,FALSE returns fglrx to the old behavior).
Anyway there is a bug report on ati.cchtml.com now.