It means that you either
It means that you either have a mis-configured server (have you looked up the meaning of 'mime types'?) or that the validator is tripping up over the fact that you have style tags in an external stylesheet where they do not belong!
Me thinks it's a
Me thinks it's a mis-configured server (check the headers).
P.S. Hugo - have you noticed that the forum spell checker is always showing 'no mistakes' even when there are some?
Noticed , and there was me
Noticed! , and there was me tinking mi spelling had becom absolotly perfect.