Infraction: 6. Do not post unless you have something new and worthwhile to say.
Message to User:
Explain why you believe it, or you're wasting our time.
I believe that haste% is calculated slightly differently from what is posted here.
To calculate the cast time of a spell after applying haste rating do the following:
(supose we are using fireball with 3 seocnds cast time
(3 seconds)/(1 + Haste rating/1570)
this produces basically identical results to your method, but will show diminishing returns for rating that get high