Also experiencing this.
Started when I walked into Blackrock Cove.
Not internet related, and the game was working beautifully up to this point.
mid-2010 Macbook Pro, OSX updated
i7 processor
4GB RAM
NVidia GT 330M 512mb
Other games like XCOM: Enemy Unknown, Diabo III, etc. work fine at medium settings, but now even at 'very low' this game does not run at a level which is playable.