Stumbled into this in the middle of a wakeful night, and despite the rubbish name it turned out to be rather an interesting picture. It's French so maybe some of our European boardies will have seen it, sort of a sub-Mulholland Drive type story centred around a young couple who get tangled up with the husband's older boss and his (apparently) disturbed wife. The main reason I decided to watch it is that the young wife is played by the ever-fascinating Charlotte Gainsbourg, an actress I find very compelling in whatever she does. The older wife is played by another favourite, the very English Charlotte Rampling who seems quite comfortable playing a Frenchwoman here. Great performances by both women in a film that requires your complete attention to understand what's actually going on.
I have my own theory but that's just from watching it once, I'll need to get it on DVD for repeated viewing to figure out if I'm right.
Oh, the title is derived from the rodent that gets stuck in a pipe in the young couple's house, and provides the seed for a memorably creepy scene later on. It's given rather a sinister significance in the film, obviously the world 'lemming' isn't perceived as comical in France the way it is in the UK.
http://www.imdb.com/title/tt0415932/