css validator question

Hi,

I can't seem to use your css validator with my external style sheet. I
get this message:

Target: http://www.cruzio.com/support/css/supportstyle.css
I/O Error: Unknown mime type : text/plain

I'm unsure what to do to fix the problem, as I don't know what it really
wants.
Yes, of course the style sheet is a text file, it seems to work, and
validates with other CSS checkers.

Can you help me?

Thanks,
John Govsky
john@earthdance.com