OK, Thanx a lot:
In /usr/share/applications/hildon/panucci.desktop I changed:

X-Osso-Service=org.panucci.pannucciInterface

to

X-Osso-Service=org.panucci.panucciInterface

Now the application starts when I click on the desktop item.

I recognized that the way to open a file/folder has now moved to the playlist-menue. I would prefere a more direct way to access a media file from the main user interface.