Installers are so pesky! We have some of the leading products for building installers. We have written a ton of Applescripts to smooth the process and each time, the installers come up with some new symptom to keep things from working the way they should. It is uncanny.
I think that the installers are possessed.
Why else would we not be able to build the Mac installer between beta 3 and beta 4?
Definitely Installergeists.