differences between upload / uri

Hi everybody,
it seems that there are some differencies between the "URI" css-validator
and the "upload" css-validator.

For example, try to check your own css :
http://jigsaw.w3.org/css-validator/style/general.css
If you check it "by URI", the css-validator will declare that it's a valid
css, but display some warnings.
If you check it "by upload", the css-validator will only display the same
warnings (and don't say at any time that it's a valid css).

I have the same probleme with my own css, and it's a bit confusing... Is my
css valid or not ??

So please, decide which css is valid or not, because these css valid and not
valid are quite strange.

Benoît GANNE.