Discount on attribute

[beeza]

I sell clothes with different sizes as attributes.

Using AJAX Attribute Manager I'm able to set an additional price for a size.

Ex: Price 100$, size large +10$ =110$

I'm using Easy Advanced Specials to handle discounts but the discount is not calculated on the total sum.

Ex: 10% discount. I want the price to be 0.9*110$=99$ but instead it's 0.9*100$+10$=100$

 

Any ideas? Please.