the ati-gatos ebuild install a binary version of the gatos drivers. i suppose that this version is in x86 format as it don't want to run on my ppc ibook. I think the solution would be to use the sources provided by the gatos project to patch the xfree sources before compiling...
You should emerge rsync, ati-gatos has been masked on PPC for quite some time now. I agree that this would have to be an option included into a future xfree build and will look into this, thanks.