BIG letters.. Validation XHTML

I was trying to validate my doc, as XHTML.

And I had:

<LINK href="/style/css/gaestebog.css" type="text/css" rel="stylesheet" />

And the page just keep telling me that there was no attribute called href

Grrrr the hole reason was that the LINK was in big LETTERS.

I changed it to: <link href="/style/css/gaestebog.css" type="text/css"
rel="stylesheet" />

And now all works fine

I think you need to add in the help text when this brobel comes thet it can
be that you have used big LETTERS.

Would have saved me 2 hours of trying to find the error

Thanks :)