Lately, I haven't written about as many movies as I'd like to. I've seen some good, bad, and bizarre movies, but none that really had anything to do with asexuality. And even that is very broad in my mind-- movies that relates somehow to an asexual experience, movies that talk about relationships in an uncommon way, and movies with possibly-ace characters are all relevant. While some movies about gay characters (The Celluloid Closet, Maurice) seem relevant, most don't. Even though the characters may be queer, the relationships portrayed are conventional. However, a film like Amelie, which is about straight people, seems oddly asexual, probably because Amelie's ways of going about relationships are so unusual.
And then you have the issue of an asexual film versus one that's just chaste or family-friendly. It would take a lot for me to call any movie with a G or PG rating asexual. Many people talk about asexual themes in WALL-E, but the movie is rated G and is about robots. How much sexual content could that film contain, under any circumstances? However, a movie like Withnail and I, which could contain overtly sexual content but does not, can be called wildly asexual.
I think it's the same reason why it can be harder to know you're ace than to know you're gay or straight. Noticing something that doesn't exist (in this case, your sex drive) isn't always easy. In the case of films, I'm looking for asexy content, and I still have a hard time finding it. I seem to write about a lot more books, because it seems like they can be more "out there" than movies and cover more obscure topics. I also never thought I'd say this, but it's easier for me to read a book (where I can read a page at a time whenever I have a minute) than to watch a movie these days. But, I still have a crazy love of movies, and the more plotless the better. It's sort of annoying to look for asexual themes in every movie I see, but I just can't help myself.