Just to make sure I am not missing anything:
XBOX 360 updates done. (although I DO have an earlier model of XBOX360)
Skyrim latest patch in.
Multiple reboots and tries.
Archery skill at 32 (at least) Kajit, points spent 3/5 on archery
Eagle eye unlocked.

Pull both triggers, and no zoom for archery.

Change controllers, no zoom.
block with shield =yes.