3.33 > 3.4 It can't find CSS

I'm not really a HTML noob and I do understand from the changelog there is something changed by the way it handles CSS files.

I did an update to 3.4 and it simply doesn't find the CSS file. At least, that seems the case (http://allaboutsketchup.fizion.nl/). I think it has to do with this line:

Then again, don't see strange things if I compare it to ither information. Think I do something stupid but can't see what. Hope someone has an answer.