Now it gets really weird. I set up a virtual machine running debian 6.0.6 as my dev machine - on this machine, the segfault occurs too! (I have to ask my friend what version he succeeded with).
This installation is really bare and fresh, from an installation CD, upgraded to the newest versions... set up _only_ the the necessary things: apache2, php5, mysql-server ( + unrelated such as ssh).

The VM specs:
PHP 5.3.3-7+squeeze14 with Suhosin-Patch (cli) (built: Aug  6 2012 20:08:59)
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies
    with Suhosin v0.9.32.1, Copyright (c) 2007-2010, by SektionEins GmbH

Linux imagedose 2.6.32-5-686 #1 SMP Sun Sep 23 09:49:36 UTC 2012 i686 GNU/Linux


My ubuntu machine:
Linux dispy 3.2.0-32-generic-pae #51-Ubuntu SMP Wed Sep 26 21:54:23 UTC 2012 i68


I don't know how to you the VM (VBox-image), my volume's limited :X