Not showing in FF29 Rated 5 out of 5 stars
After upgrading to FF29 and getting tons of probs including bottom taskbar disappearing I succeeded to return it with The Addon Bar (restored) but from the add-ons I had there in FF28 now Share on Twitter button is not showing anymore! Help?
Use the "Customization Mode"
The addon bar (bottom taskbar, as you said) has been removed from Firefox 29. I've already updated the extension, so that it's icon now appears on the toolbar.
If it is not visible for you, bring it back to the toolbar from the "Customization Mode".