Yup, I have the same problem with the text, I don't have problem to play in english, but my nephew can't.
A solution for me was, use the convertion to fit the game in one dvd, then manually copy the files:
B.Texture_es.Cache
B.Texture_es.Toc
H.Misc_es.Cache
H.Misc_es.Toc
H.Texture_es.Cache
H.Texture_es.Toc
in the folder "Cache.Windows"
I made two installations, one from the convertion and the other from the game that i downloaded, and then i compared both "Cache.Windows" folders to know the files i need.
Pd: Sorry for my english