No Oscar Nomination for Christopher Nolan's Directing?

Why, oh why did Christopher Nolan not get a nomination for Best Director for Inception? I'm glad he was nominated for Best Picture and Best Original Screenplay, but not getting a directing nod seems ludicrous. To be fair, I haven't seen any of the nominees in the category (I'm behind on my viewing, okay?), but I'm having a hard time not seeing Nolan's masterful guiding hand behind Inception not ranking with any of them.

So, anyone out there who has seen some of these other films think they are better directed than Inception?