Calculation Wrong with Conservative Casting

Hi,

i just instilled my Amu with Conservative Casting. Its meant to be 8% reduced mana Cost, but instead it counts as just 8 mana reduced.

Example on my Spark Cost:
Cost at the moment 150 mana
with Conservative Casting its 142, it should be 138

Example on my Mana Tempest:
Cost at the moment 156 mana and 47,42 per second
with Conservative Casting its 148, it should be 143

Im not sure if i do something wrong, but please look it up it seems wrong to me

Bump.

Conservative casting math is broken all over the place.
With talents and + spell level it recudes my spells by a few points hardly worth mentioning.

Some spells are -1 mana on a 400 mana spell, and others are 30 points on 800 mana spell. It makes no sense.