Cannot load .rgb texture

Hi all. I am trying to load a mesh which uses .rgb and .rgba textures. I am using the sample framework and get this error when I try to create the entity:
OGRE EXCEPTION(5:ItemIdentityException): Cannot find codec for extension rgb in Codec::getCodec at ..\src\OgreCodec.cpp (line 62)

I am not that familiar with ogre or python ogre, but I thought ogre was using devIL, which I know can load .rgb. Sorry for my ignorance, but Im not really sure where to start with this. I would really appreciate some pointers.

Thanks,
Gareth