The idea of the cache file was to speed up loading time, store the data from the movie and tv arrays directly to a single large xml file. While it does speed up loading time significantly I have so far been unable to iron out all the problems, hence the disable cache option.
I'll have another look at it over the next few days, but to be honest with you, it hardly seems worth it just to make the program start a bit quicker, if I can't get this working properly soon then i will just scrap it as a bad idea.