tada!
Ok. When you install ram in a G5, it is NOT like the old power macs. The olds ones were like this 1|2|3|4|5 1|2|3|4|5. The new PowerMac G5s go likes this 4|3|…
Return Shapeshifter to all defaults then Delete SS preference files then reapply themes. This has happened to me on more than one occasion and it has always worked