Do the ids in the array appWidgetIds of the method
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
all belong to my app?
If so then there are some appwidgets somewhere in the nirvana of my android, because if I delete all appwidgets there still remain some ids in the array which are not shown on my homescreen. :-(
Is there a way to remove ALL widgets?
I got it solved: I uninstalled, then reinstalled my app and after that all the ghost widgets were gone.
In conclusion: all the ids in appWidgetIds are the ids of my app.