Norton and U-verse

I have Norton Internet Security 2013 and U-verse. I have noticed that my U-verse speed fluctuates randomly. When this happens, it isn't possible to view videos without them freezing and then unfreezing a minute or so later. I have had AT&T change out the Router and all of the cables. It seems to me that the only other thing that could be the cause is Norton running in the background.

 

Are there things that I can disable in my Norton that may prevent my speed degredation?