I dont know how carbonite handles these, sometimes you get a popup either to complete or to accept a quest in the objective bar.
For example right now I got a popup to accept a quest in my objective bar for the "Default WoW objective bar"
But while using carbonite I don't see it at all, or maybe I am seeing it but don't know where it is cause I'm blind? :P
![Banana!](//cdn-wow.mmoui.com/images/style_mmoi_wowi2/smilies/banana.gif)