Life Tap issues

Life Tap issues

Third time editing, apologies..my mind is elsewhere, sorted now :)

Naked and untalented, it bugs.
Naked and with the equivalent talent (improved life tap in affliction tree) partly slotted, 1/2, it bugs.
Naked and with the equivalent talent fully slotted, 2/2, again it bugs.
Geared up...it remains bugged :)

Namely, something happens because of ...spell dmg bonuses? Something else?.. that makes it:

!) cost much greater amounts of health to use, while giving back exactly the mana it is suposed to.
Last rank is 420 health for an equal exhange of 420 mana. It actually takes 1k+ of my health to give that 420 mana back!

2) ignore the relevant talent, be it 1/2 or 2/2, and continue to cost exactly the same regardless

edit: The Plagueheart Set works as should btw..8-set bonus corrctly reduces the health cost by the percentage stated. Even in our case. So the issue lies in general.

Urgent for me, as class + this = useless. Feel free to redefine the priority