PSPP-BUG: Installation PSPP fails

[Christian Kempgens]

My MacBook Pro 4.1 (2008) runs with OS X 10.8.2 Mountain Lion. It has a 2.4 GHz 
Intel Core 2 Duo Processor.

In addition, I have installed XQuartz, successor of X11, Xcode 4.6 and Command 
Line Developer Tools.
From Jeremy Lavergne's home page, I downloaded the installer for PSPP 
http://lavergne.gotdns.org/projects/pspp/ 
for OS X 10.8 (x86_64). 
When I start the installer, I get the following error message:

"The installation failed.
The Installer can't locate the data it needs to install
the software. Check your install media or Internet 
connection and try again, or contact the software 
manufacturer for assistance."

My internet connection was intact, and all the data needed for installation 
should be in the file "pspp-devel-0.7.9-44-10.8.mpkg", right?
Does anyone know how to solve this problem? 
Thanks, Christian.