Question regarding melee attack speed

[Arctagon]

I returned to WoW after a rather long hiatus. There have been many changes obviously, and I wanted to continue leveling my DK.

Specing Frost, my melee attack speed goes down to 2.76 due to Icy Talons (20% attack speed increase). I am using a weapon with 3.4 in speed and have 2.63% in melee haste. When I calculate this, I get an entirely different number. Icy Talons alone should change the attack speed to 2.72. If I add 20% attack speed to 2.76 and then the 2.63% melee haste, I land pretty much at 3.4, but that's definitely not the way it should work, and it's most likely fortuitous.

So why does it land on 2.76? I get other numbers when calculating Improved Icy Talons as well. Is this a bug or something?

[Nyanmaru]

Icy Talons 20%, IIT 5%, Haste from rating 2.63%
1*1.2*1.05*1.0263 = 1.293138 = 29.3138% haste total

3.4 / 1.2 = 2.833 (IT alone)
3.4 / (1.2 * 1.0263) = 2.760 (IT + your haste)
3.4 / (1.2 * 1.05) = 2.698 (IT with IIT)
3.4 / (1.2 * 1.05 * 1.0263) = 2.629 (IT with IIT + your haste)

Keep in mind, you don't decrease your swing time, but increase the number of hits per time.
It's not 3.4 * 0.8 but 3.4 / 1.2

[Arctagon]

Ah, yes. Of course. It's all coming back to me now. Thank you for your trouble.