Xbmc and tv show library detail - strange problem

I have a bit of a strange problem. I have a media library maintained by Media Center Master. So far as I'm aware that creates XBMC metadata files,etc. It all worked fine under windows 7.

I've updated to windows 8 and now my tv library doesn't show the episode names or the media library descriptions of my old episodes. However, anything that has been added recently works fine.

Does anyone know how to sort this? Thanks