Seriously. All I was trying is to get an occlusion bake done. Well, I imported the model which already had a texture assigned. I created a blank new one in the image window. Then doing the bake. Now when I try to do it again blender just tells me that it can't find an image to bake to. Great, what now? Creating another blank new one didn't work.
I've been fiddling with it for hours only to come to the conlusion that the UI designer needs to be shot and hanged, twice. Grrr...
edit:
Great, must have been some internal error as it works now as intended... :(
edit2:
No, user error. :P
Apparently I have to have the object I want to do the baking on selected in object mode...