Klaus, you may not have the "benefits" of using a 2006 polycarbonate Intel iMac running Mac OS 10.7.5 . . .Just downloaded the stack from his Dropbox and did not have any problems!?
Tomorrow I shall try downloading onto my 2005 polycarbonate PPC iMac running Mac OS 10.5.8
(working on my usual basis that backwards is the new forwards).
And, on a more serious note, I shall have a go on a machine at work running Ubuntu 14.04.