Not sure what's causing the problem exactly, but here's a few things I noticed:
- You seem to be including jQuery merely for the fisheye effect; increases load time a bit.
- There's an <else /> tag in the source, meaning there's a broken conditional somewhere in your templates, potentially displaying unwanted content.
- The W3 validator can't check it because there's a utf-8 character you've specified an ISO-8859-1 charset. Fix that and see if it validates.
- Your CSS isn't stored in an external stylesheet meaning it isn't being cached.