Carbonite dropping fps while in cata dungeons

[Nensec]

For some reasen when i have carbonite enabled inside an instance my fps drops to 15 or less, but a weird thing is when i open a right click menu the fps drop dissapears.

I havent had the chance yet to run an instance with lua errors on so will edit when i get more info

edit:
here is the culprit: http://screenshot.xfire.com/s/107807751-4.jpg