Why isn't my Sub Theme's CSS file showing up? I created a sub theme which is intended to just have a few color changes and background image changes. 

The Base theme is called limon. The sub theme is limon_orange. In the sub theme, i have a unique style sheet that I want to use to override the base theme styles via cascade. In the limon_orange.info file I have this  line:

stylesheets[all][] = orange.css

The sub theme works, but orange.css is never used. What am I missing? Why is orange.css not loading?
Any change in .info does not take effect only by clearing cache. Remember to clear the theme registry. You can do this by just going to the admin/appearance and saving it.