How to unpack installer (or corrupt installer)?

[jens]

MD5 is correct.

I don't know that much about Linux, but a common problem with the installer in the past has been:
1. There has not been enough free space on temp or where you want to extract it.
2. It needs executable permissions for the temp (or is that writeable, can't 100% remember).

Have you checked the suggestions in this thread? http://www.frictionalgames.com/forum/thread-22830.html