So has anyone any ideas I could try next?

   Hey BENT - My Start Screen worked good for 3 weeks, then I had the exact same problem - some pinned projects would not go away after un-pinning.
   Then a few weeks after that, most of the smart screens don't open. The screen for Videos says I'm not connected to the internet, but I am of course.
   Since then I stopped using it. Hope you get a good reply. I'll keep an eye on this thread.

Thanks anon.
Would like to here from others who have this same irritant before I start a Problem Report not that I should have to... 
As I said before... For me at least the start screen is a “updated feature” which is a "downgrade"

Pleased to say that Jamaica Plain has resolved this issue.

   Same here, sometimes an update resolves problems, not always.