Cannot fetch remote JavaDocs: gzip

Hello, I am trying to attach a javadoc to a jar file. In particular, I am attaching the URL "http://tapestry.apache.org/tapestry4.1/apidocs/" to a Tapestry jar via "Specify Javadoc URL" in the Project Structure panel.

Now, after having done so, when I press Ctrl-Q on e.g. org.apache.tapestry.html.BasePage in an editor window, the expectect pop-up windows appears, but it says "Cannot fetch remote JavaDocs: gzip".

Am I doing something wrong? I am running IntelliJ 6.0.5 #6180

Thank you for your help!