Crashes when in movie mode

I have a large collection of movies and TV shows, when I access the TV shows XBMC works fine but as soon as I try and 'look' at the movies XBMC crashes. This happens on both my computers one is running Snow Leopard 10.6.8 and the other is on the latest version of Kubuntu.
Has anyone had the same problem? And Fixed it?If so please tell me how.
Cheers, Brian.