Rails 3.1, stylesheet assets not being reloaded correctly?

Hi,

I'm working on a Rails 3.1 project at the moment and having a hard time
getting the stylesheets properly loaded.

My application.css.scss looks like this:
/*
* This is a manifest file that'll automatically include all the
stylesheets available in this directory
* and any sub-directories. You're free to add application-wide styles
to this file and they'll appear at
* the top of the compiled file, but it's generally better to create a
new file per style scope.
*= require application-pre
*= require_self
*= require application-post
*= require formtastic
*/

body {
  background-color: #000;
}

which is being served just fine:
Started GET "/assets/application.css?body=1" for 127.0.0.1 at 2011-11-01
10:57:08 +0100
Served asset /application.css - 304 Not Modified (0ms)

No I change background-color to #fff and it seems to be served right:
Started GET "/assets/application.css?body=1" for 127.0.0.1 at 2011-11-01
10:57:55 +0100
Served asset /application.css - 200 OK (5ms)

But the page looks still exactly the same and when I look into the CSS
file it still says #000. Does anyone know what's wrong here?

Are you caching the Stylesheets in your layout?