Damn, no pop-up screen.
So I took the Civ4BuildingXML and added ART_DEF_MOVIE_CAT_LIB to the Catacomb Library.
In ArtDefinesMovie xml I created a ART_DEF_MOVIE_CAT_LIB and set the path to a folder with the library.dds
I also put your screen into the Python screens folder.
Okay, what blond noob thing did I forget?