I emerged gnome-2.12.0 on my G5 running ppc64 linux(64-bit userland), and it worked but had one backgrounds problem: 1).The desktop background was splitted by a white ribbon(see next attached picture), when I started gnome for the first time. The background became normal when it started again. 2). When I logged out gnome(normal background), and entered it again, the background content would shift a little bit up, causing desktop messed up. And it would continue to shift up when a new theme was selected. 3). The problem got away when no wall paper selected for the background. Does anyone have the same problem?
Created attachment 76603 [details] screenshot of the desktop
Created attachment 76607 [details] another screenshot
Found too there was no problem when the size of wall paper was larger than that of screen and tiled.
I upgraded to gnome-2.12.3, and the problem of background wallpaper was gone.