After each OS update, I have to re-add the Snort Dashboard widget manually.
Not sure why that's happening, if that's an issue with that widget, how packages are reinstalled, or whatever:
but after each upgrade, I have to re-add the widget to the dashboard, which then stays in its place until the next upgrade.
I think this is by design to prevent errors logged in by the widget. You should post this on the packages forums as this is not related to 2.1 in any way.