[Plugin: WPBook] Wrong letters shown in application

I just updated to 2.0.2
Everything works fine. There is only one problem:

Looking at my app via fan page tab everything ist displayed well. (https://www.facebook.com/pages/Aussen-und-Sicherheitspolitik/183526984892) tab: AuSiPol

Using the app directly (https://apps.facebook.com/ausipol/?ref=bookmarks) the german letters are not displayed in the right way.
How can I solve this problem?