Error after login. But by which application?

[Christoph Bier]

Hi all!

After I upgraded (security fixes) a Hoary machine running GNOME and
migrated my Breezy laptop from GNOME to Xfce there's an error on
both machines I can't track down. After login there's an error
window with the following content (translated from german to english):

You don't have root privileges to run this application.

How can find out which application is responsible for this error? I
don't miss any functionality.

Best,
  Christoph
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