I Think I've solved it Rated 5 out of 5 stars
As you will have read on previous reviews, I kept losing the pinned Twitter Bar. It just needed reinstalling from time to time. I read another review which mentioned Pinned Tabs................So I added my own online shop to a pinned tab. That now means I have that and Twitter... Touch wood with the two - the Twitter one has behaved itself.This user has 2 previous reviews of this add-on.