rewrite rules for wordpres 3.0.1 multi site with subdirectories nginx

Question

Hi,

I've been trying to use the solution from this post: http://stackoverflow.com/questions/3488861/rewrite-rules-for-subdirectories-in-wordpress-3-multiuser-with-nginx

But I keep getting an "unknown directive if(" when restarting nginx. Am I doin' something wrong or do I have the wrong rewrite rules or what?

Thanks for your help.

Lars