FieldError when accessing admin-site for flatpage

[gagabla]

When accessing the admin-site for flatpages (creation and modification) i get the following error:

FieldError at /admin/flatpages/multilingualflatpage/add/

Unknown field(s) (content, title) specified for MultilingualFlatPage

Additional Information in the error page:

Request Method:     GET
Request URL:     http://deep-white.eu/admin/flatpages/multilingualflatpage/add/
Django Version:     1.3 alpha 1 SVN-14739
Exception Type:     FieldError
Exception Value:     

Unknown field(s) (content, title) specified for MultilingualFlatPage

Exception Location:     /usr/lib/python2.5/site-packages/django/forms/models.py in __new__, line 236
Python Executable:     /usr/bin/python
Python Version:     2.5.2
Python Path:     ['/var/www/web0/applications', '/usr/lib/python2.5', '/usr/lib/python2.5/plat-linux2', '/usr/lib/python2.5/lib-tk', '/usr/lib/python2.5/lib-dynload', '/usr/local/lib/python2.5/site-packages', '/usr/lib/python2.5/site-packages', '/usr/lib/python2.5/site-packages/PIL', '/var/lib/python-support/python2.5']
Server time:     So, 28 Nov 2010 13:06:21 -0600