I wonder if the Apple developers are aware of this issue and if it would help to report it...As far as I've heard, Apple tends to neglect older hardware, but in the case of the GMA 950 it was still standard in MacBooks and MacMinis when Leopard came out last year. Maybe there is at least little hope that they do something about it...
I had some odd color bugs (that coldn't be undone with 'undo') with some color filters, too. I guess this is because of the GMA 950/Leopard as well?
And, as seen in demo video 3, the selection tool usually "freezes" at some point while dragging a selection frame around something (zebra eye in the video), requiring you to wait some seconds (less in the video) until you see your current frame as it is (I hope you understand what you mean, it is the lack of "fluidity" in the frame dragging). Is this something that can be fixed?
Anyway, LiveQuartz easily remains my image editing tool of choice:
a very good self-explanatory interface, polish, stability and few bugs, speed, low file size, all the functions I need, Leopard integration, fast support in the forum,
It easily beats clunky, buggy and unpolished X11 Gimp in EVERY single one of these categories, despite of the apparently much larger user (and developer!) base Gimp has. In the very short time I tried Gimp with my low skills and demands I already found so many bugs (program crashs and very obvious localization flaws included) using only the simplest operations. Then I tried the apparently discontinued "Seashore" and FINALLY for some some small post in a Mac forum, I discovered LiveQuartz.
It should really be used and known by more people...