Newpoints?

I already have Newpoints. It just that the forum rule deducts threads and posts points.

for example,

Each thread rewards 4 coins and in the forum rule I want to deduct 10 coins I have to set it to -2.5 (-2.5 * 4 = -10 coins). however it deducts 5 coins from posting in that forum. Like it is doing what I want, but I want users to earn 2 coins from posting on that forum rule though.