Vienna freeze sometimes

[MacDisein]

I am using Version 3.0.4 :a86edf4: on MacOSX 10.8.5 and in some situations Vienna freeze and has to be force quit.

I subscribed to http://www.wunschliste.de/xml/atom.pl?news=1 and if you double click an article to open the corresponding article on the Wunschliste website an error message appear and sometimes (if a Netflix slide in advertisement is showing) Vienna freeze.
Maybe this is reproducible.