Parse Errors From CSS Validator

Hi,

I am trying to validate a css file using the w3c validator. I am
getting a ton of parse errors which I do not understand. The lines in
question seem to be working in the browsers, so I don't know why they
wouldn't parse in the validator.

Here's an example.

These lines...
.center_align_text {
     TEXT-ALIGN: center;
}

...are generating this error...
Line: 21 Context : .center
Parse Error - center_align_text { TEXT-ALIGN: center; }

Any thoughts?

Thanks,
Jerry Faux