Python 'Nonetype' Error

Hi,

Ive been working on an interior design of my kitchen in blender. When I finished it and hit ‘Render’ in yafaray it first gave me somekind of subsurf calculation error which I managed to fix, but then it also gave me this error:

http://img706.imageshack.us/img706/3107/pythonerror1.png

I dont know if this has anything to do with this error but somehow the camera was also gone when i opened the file today, right before the problem occured.

I use blender 2.49b, python 2.6.2 and yafaray 0.1.1 for this project.

Thanks in advance.