If you're on the Campaign page the "My favored Threads" link in the Forum menu wont work, it's the same on the Matches page:
http://battlelog.battlefield.com/bf3/matches/
On Premium user profile pages, the Premium carbon header gets put as background.
Also, if you open the "My favored Threads" and then open BBLog and then open "My favored Threads" again you'll have two My favored Threads lists stacked on top of each other.
EDIT: It doesn't work on the Age Rating page or the Credits pages neither.