strange CSS validator error

Hello

I am trying to verify the CSS on one of my pages and I am getting the 
following output:
------------------------------------------------------------------------


    Target: http://www.eternalrise.com/feedback

Please, validate your XML document first!

Line 13

Column 3

The element type "HR" must be terminated by the matching end-tag "</HR>".

------------------------------------------------------------------------
My pages validate fine when using the XHTML validator, and I'm not even 
using a "<hr>" tag, so I don't get it.

Can you please check this out and get back with me, I would greatly 
appreciate it.

-Thanks,
Sean