Link in news feed story does not link to native iOS App, when user didn't enter an additional text.

Link in news feed story does not link to native iOS App, when user didn't
enter an additional text.

In my iOS iPad app, users can post to their Facebook timeline and share
their score using FBWebDialogs. Other users can tap on the link in the
post and either the AppStore will open or - if installed - my native app
itself will open.
I found out that opening my native app (if installed) from Facebook posts
only works, when the user did enter some text in the sharing dialog. If
there is no text in the dialog, Facebook App will open the AppStore app
and display the app instead my native app - even if my app is installed on
the iPad.
In my params to the FBWebDialog, link is set to AppStore URL, have my
AppID included and deeplinking is turned on in the settings.
Anybody know about a solution to this? Thanks for any hint!