CSS Validation

I'm a little frustrated.  I've been trying to validate my CSS for a while now and can't get any of my style sheets to validate.  I've made all the suggested changes unitl there are not more warnings or errors displayed and my CSS still is not validated.  All my pages are valid HTML 4.01 Transitional.

So, why won't my CSS validate?  I would really like some help.  

thanks,
greg davis