Originally Posted by pretence
or maybe I should use the vesa Driver instead, no?
If your graphics card has two ports try the other socket!!
The vesa drivers performance is poor and only 2D. ( give it a go change "fglrx" to "vesa" in xorg.conf )
I have never seen this problem before and suspect a corrupt install ( is it a fresh install ) ?
If it is I would try a clean install (re-install fedora )