CSS Mime Type transferred as Zip in Chrome - 15 second delay Resource interpreted as Stylesheet but transferred with MIME type application/x-gzip: "http://www.energyjustice.net/modules/system/system.base.css?m7sb47". 

I turned off the CSS aggregate and compress option, and emptied the Chrome browser cache.  So I'm not sure why I'm still getting this?

If there is nothing in the cache, this error causes Chrome to have a 15 second delay in transferring the system.base.css file.  Firefox works fine.

Drupal 7.14
Apache/1.3.41 (Unix) with mod_gzip/1.3.26.1a 
Chrome 20.0.1132.57

It looks like mod_headers is installed.
This is a TOTAL shot in the dark here, but:

1) are you running "Avast!" ?

2) If you load your site and look at network traffic (e.g. "Net" panel in Firebug), are there any 304 responses from the server?