(Watched) Threads with Unread icons Rated 4 out of 5 stars

In TBird the Threads with Unread as well as the Watched Threads with Uread do not have any icon over here! I have the default theme. To make sure, I removed them from the toolbar, and reinstalled the xpi, but still no icons. I have one of them on the toolbar but instead of icon there is a placeholder - just a small area that can be clicked.

This review is for a previous version of the add-on (0.4.5.2).