Discount Terms does not work

Hi.

I have some issues with the set up of Discount Terms.

I want this result:

Amount 1000
Discount 10% (10% 10 net 30)
New amount after discount 900
VAT 25% 225
Total amount 1125

I get this result:

Amount 1000
Discount 10% (10% 10 net 30)
New amount after discount 1000
VAT  25%  250
New VAT After Discount 250-25= 225
Total Amount 1225

The system only give Terms discount on VAT.
This is not what we want.

I don´t know how too make this work, seems like a bug.

My set up is as follows:

Setup --> Account Preferences --> General
- Include tax for term discount – unchecked
- Include shipping for term discount – unchecked

Setup --> Accounting --> Accounting Lists --> Terms