[PyQt] QtGui error after installation

[Nicola Creati]

Hello,
I just installed sip 4.11.2 and PyQt4 4.8.1 and when I import 
PyQt4.QtGui I get the following error:

"metaclass conflict: the metaclass of a derived class must be a 
(non-strict) subclass of the metaclasses of all its bases"

If I reimport PyQt4.QtGui after the error everything goes well.
I'm using Linux Ubuntu 10.10 64-bit and python 2.6.6.

Thanks,

Nicola