wordpress mu lighttpd rewrite

Try the following in your lighttpd.conf, probably inside of an appropriate host conditional:

url.rewrite-once = (
"^/(.*)?/?files/$" => "index.php",
"^/(.*)?/?files/(.*)" => "wp-content/blogs.php?file=$2",
"^/([_0-9a-zA-Z-]+/)?(wp-.*)" => "$2",
"^/([_0-9a-zA-Z-]+/)?(.*\.php)$" => "$2",
"." => "index.php"
)