i cannot anymore as it is solved...

but it involved also rotating around a point.
i use gltranslatef and glrotatef also i do a manual rotatation around a point to get the correct new x point. Both methods were a bit out of sync and i had some nasty left over code in the box drawing that overruled the outcome coords partly, next i 'fixed' a part that was correct in the first place and i got some chaos :-( .

Now i need to bring back the more then 2 color gradients code part back to live.