Confusing speed limit sign.

When leaving the village of Easton which is a 30mph limity there are two 40mph speed limit signs (in the direction of Norwich this is). There are no repeater signs after this but as you reach the right hand bend in the road on the left is a National speed limit sign. Coming in the opposite direction if you come off the Southern by pass (from the west bound carriageway) there are no signs stating if this is indeed a 40mph limit and it looks like it is still a national speed limit on this road going in this direction. Was there ever an order to change this speed limit? If so then the signage is incorrect and needs fixing as it would be difficult to enforce such a speed limit with the signage the way it is at the moment.