"If I drag & drop the Thunderbird icon a few pixels away from the Unity Dash, it springs back into position the message counter reappears. If I don't do this however, it stays broken."
Exactly the same for me too.
"If I drag & drop the Thunderbird icon a few pixels away from the Unity Dash, it springs back into position the message counter reappears.
If I don't do this however, it stays broken."
Exactly the same for me too.