Agreed, I think Tarkovsky and Rerberg are a good example of this
So apparently Satantango is mass-market...
Never mind, I resolved the issue myself.
If anyone else has this problem: Reset the camera and the Anamorphic mode will work fine.
That lens is all over ebay and the internet in general. It was the lens that shipped with Zenit cameras back in the day, so there's just loads of them around. I have one, it's wonderful.