Fan art not working

Hi all

I have xbmc on my raspberry pi send my ipad2. I use wdtv live boxes so I've done all my fan art moviesheets and folder jpegs with thumbgen. When I use xbmc on either iPad or raspberry pi it shows my custom movie jpeg folder created from thumbgen but no fan art. I have to go to each movie one by one and refresh and select fan art manually. My tv shows work fine but I think that's because I never used thumbgen on those files (got lazy)

So how can I get xbmc to refresh all movies? Without me doing each manually or without me having to delete the thumbgen files?

Thanks