Dominik, I am afraid you are mixing up some problems here :) The initial reporter doesn't even have a X700 card like in bug #22985. Adam has a X600 card, and the fix for #22985 does not apply. As Adam reported, disabling DRI helped.
This bug should be closed, since it's now working for the initial reporter. Some of the later comments of other people belong to other known bugs.
Dominik, I am afraid you are mixing up some problems here :) The initial reporter doesn't even have a X700 card like in bug #22985. Adam has a X600 card, and the fix for #22985 does not apply. As Adam reported, disabling DRI helped.
This bug should be closed, since it's now working for the initial reporter. Some of the later comments of other people belong to other known bugs.