[Qgis-developer] installing 1.7 standalone Win XP: Couldn't load PyQGIS., Python support will be disabled.

[Janneke Qgis]

Dear all,

I've just tried installing the standalone version of Qgis 1.7 on XP, and 
after starting the program I get the following error message:
--------------------------
Couldn't load PyQGIS.
Python support will be disabled.


Traceback (most recent call last):
   File "", line 1, in
RuntimeError: the sip module implements API v5.0 but the qgis.core 
module requires API v8.1


Python version:
2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1310 32 bit (Intel)]

QGIS version:
1.7.0-Wroclaw 'Wroclaw', 63ecdd7

Python path:
['C:/PROGRA~1/QUANTU~2/apps/qgis/./python', 'C:/Documents and 
Settings/Admin/.qgis/python', 'C:/Documents and 
Settings/Admin/.qgis/python/plugins', 
'C:/PROGRA~1/QUANTU~2/apps/qgis/./python/plugins', 'C:\\Program 
Files\\ArcGIS\\bin', 'C:\\Qgis\\apps\\qgis\\python', 
'C:\\Qgis\\apps\\Python25\\Lib\\site-packages', 
'C:\\WINDOWS\\system32\\python25.zip', 
'C:\\PROGRA~1\\QUANTU~2\\apps\\Python25\\DLLs', 
'C:\\PROGRA~1\\QUANTU~2\\apps\\Python25\\lib', 
'C:\\PROGRA~1\\QUANTU~2\\apps\\Python25\\lib\\plat-win', 
'C:\\PROGRA~1\\QUANTU~2\\apps\\Python25\\lib\\lib-tk', 
'C:\\PROGRA~1\\QUANTU~2\\apps\\qgis\\bin', 
'C:\\PROGRA~1\\QUANTU~2\\apps\\Python25', 
'C:\\PROGRA~1\\QUANTU~2\\apps\\Python25\\lib\\site-packages', 
'C:\\PROGRA~1\\QUANTU~2\\apps\\Python25\\lib\\site-packages\\win32', 
'C:\\PROGRA~1\\QUANTU~2\\apps\\Python25\\lib\\site-packages\\win32\\lib', 'C:\\PROGRA~1\\QUANTU~2\\apps\\Python25\\lib\\site-packages\\Pythonwin', 
'C:\\PROGRA~1\\QUANTU~2\\apps\\Python25\\lib\\site-packages\\wx-2.8-msw-unicode']
---------------------------

Is there anything else I should install or set?

greetings,
Janneke