Description:
when starting qgis (eighter from console or from a launch menu) it gives the following message in a small dialogue box:

" Couldn't load PyQGIS.
Python support will be disabled.


Traceback (most recent call last):
File "", line 1, in
RuntimeError: the PyQt4.QtCore module is version -1 but the qgis.core module requires version 0


Python version:
2.7.1 (r271:86832, Jan 6 2011, 11:45:30)
[GCC 4.5.2]

QGIS version:
1.6.0-Copiapo 'Copiapo', exported

Python path:
['/usr/share/qgis/python', '/home/huub/.qgis/python', '/home/huub/.qgis/python/plugins', '/usr/share/qgis/python/plugins', '/opt/grass-6.4.0/etc/python', '/usr/lib/python27.zip', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-linux2', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/lib/python2.7/site-packages', '/usr/lib/python2.7/site-packages/gst-0.10', '/usr/lib/python2.7/site-packages/gtk-2.0', '/usr/lib/python2.7/site-packages/wx-2.8-gtk2-unicode']"

After clicking ok qgis start with obviousely much less options.

Additional info:
* package version(s)
Name : qgis
Version : 1.6.0-1
URL : http://qgis.org/
Licenses : GPL
Groups : None
Provides : None
Depends On : jasper curl qt gsl grass python2 pyqt giflib xerces-c cfitsio qwt
Optional Deps : postgis: postgis support and SPIT plugin
fcgi: qgis mapserver
Required By : None
Conflicts With : None
Replaces : None
Installed Size : 55764.00 K
Packager : Thomas Dziedzic
Architecture : x86_64
Build Date : Sun 05 Dec 2010 10:34:39 AM GMT
Install Date : Sun 05 Dec 2010 09:21:26 PM GMT
Install Reason : Explicitly installed
Install Script : No
Description : A Geographic Information System (GIS) that supports vector, raster & database formats

* config and/or log files etc.
see above

Steps to reproduce:
just start Qgis, from console, menu, or from within grass