Bug Deterrence ?

I play hunt from BC, and I find that the deterrence bug a lot, it does not block half the spells he should , I just got 100% by pala under Deterrence I have not deviated one spell or parry a single attack. I find it frustrating that his our best defensive cd is as bug.

You've probably heard of this before, but don't give your back to melee, I can prove to you that some melee hits can still bypass deterrence EVEN THOUGH they aren't supposed to. The only things that bypass deterrence (by melee) are Rune Strike, Overpower, and any positional 'behind target' requirement such as rogue ambush and feral's shred.

That being said, it tends to 'bug' out more often once you enter combat.

Patch 3.2.0 (04-Aug-2009): This ability now allows the hunter to parry spells and attacks from behind as well as in front.

Just these skills cant be parried:
-Overpower
-Chaos Bolt
-Cheapshot
-Shiv
-Counterattack (Hunter melee ability)
-Runestrike
-Engineering pyro-rocket

If a rogue cheapshots a hunter threw deterrence, that hunter loses all parry benefits from deterrence during the time he is stunned. If the rogue dismantles the hunter as well, he or she cannot regain Detterence for the disarmed duration either.