I have defeated the final Boss. ( I played on normal and it was so easy that I am almost disappointed.)

After the battle I have talked with all my companions.

After talking, I saw a box with druid spells on the screen, though my main char (paladin) was selected.

The UI overlay boxes for weapons and spells seem to have become 'sticky' with the most recent patch and don't go away for me until I click something on them. Seems very similar to your problem.

 

http://forums.obsidian.net/topic/78037-104-mouseover-ui-elements-sticking-in-place/

Edited May 4, 201511 yr by waretaringo