Comment 12 for bug 588155

>>"I've seen this bug on a machine that doesn't have gnome-do/docky installed."

That makes me a little sad, because I was really hoping I had narrowed the problem down, but it's helpful nonetheless.

After re-reading this thread, I'm starting to wonder if maybe mine is a different bug. OP's report describes an error occurring at startup, but my bug's symptoms occur well after startup. I originally thought these were related as gnome-settings-daemon errors, but maybe I'm wrong.

My new hypothesis is that some program sends a message to the X-server to redraw/update a window while several programs are running. In order to redraw/update the window, the settings daemon must supply theme, font, color, and other settings. The gnome-settings-daemon then crashes due to lack of available resources, poor process scheduling, or some other problem, and lacking settings info, the X-server reverts to the default theme. In my case, docky was at least related to the crashes-- the symptoms went away when I stopped using it-- but I'm unsure how it was causing them.

I don't have the expertise to explore this line of reasoning, nor do I have the knowledge to determine if this is sound logic. What would be nice is if some code guru out there in Launchpad Land could investigate this bug a little bit.