Hi all, Firstly, thanks very much to all who helped - much appreciated :-) I can report that the problem is fixed, but not in an expected way...... It was definitely something to do with Open GL, but what I may never know. I tried multiple versions of the NVidia drivers and nothing made any difference. Eventually, I swapped the graphics adapter for another NVidia card, and effects worked perfectly, with no software changes at all. Thinking it might be a hardware issue on the original card, I swapped it back in......and it also worked perfectly, and still is!! All problems gone as mysteriously as they first appeared. Go Figure! Anyway, thanks again to all who pitched in. Regards to the list. Paul -- To unsubscribe, e-mail: opensuse-kde+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kde+help@opensuse.org