Why is this file not being gzipped?

[mike]

http://media.xmike.com/css/style.css

        gzip on;
        gzip_static on;
        gzip_proxied any;
        gzip_min_length 1100;
        gzip_buffers 16 8k;
        gzip_comp_level 4;
        gzip_types text/plain text/css application/x-javascript
text/xml application/xml application/xml+rss text/javascript;
        gzip_disable "MSIE [1-6]\.";
        gzip_vary on;

It's a text/css file. It's 2331 bytes. Is it too small?
gzip_min_length is set to 1100...

Just wondering.

I did gzip it manually (for gzip_static) and it does work as designed.
But I want to make sure that I've got the right configuration down for
normal, non-pre-gzipped files.

Thanks :)