actually
It's not Apple geek humor but rather a problem with Stuffit Expander. Stuffit defaults itself to opening disk images, but the problem is that it is only 100% compatible with images made using DiskCopy 4.3, and 6.3 is the state-of-the-art. The solution, for both this and all future stuff, is to disable stuffit's "mount images" feature and to *always* mount images using either DiskCopy or Toast (whichever is appropriate).