Brett_Tabke - 12:21 pm on May 23, 2011 (gmt 0)

> I do not understand where the risk can be.
> I clearly state that I block any user-agent that includes the term "Preview".

Anytime you block a legit Googlebot - you face consequences. Google would not want your site in serps if they can't have a preview of it. This is probably why they make it next-to-impossible to turn off.