HansruediJoerg on "robots.txt different in GWMT compared to installed one"

I’m facing a rather strange problem. I have uploaded this
User-agent: *
Disallow: /wp-admin/
Disallow: /wp-includes/
Disallow: /tmp/
Disallow: /pdf/
as http://focusonmobile.com/robots.txt but Google Webmaster-Tools (GWMT) reports
User-agent: *
Disallow: /
This even after fetching as Google. GWMT reports
Blocked by line 2: Disallow: /
Detected as a directory; specific files may have different restrictions
Any thoughts how this can be solved?