Pricerule for Brand does not correctly calculate

I have defined a Pricerule for a specific customer in the system. This rule only gets on item brands.

One brand is defined for this customer ( Customer XYZ and Brand Nike => priority is set to 8 ), and gets a discount about 20%.

I defined one generally rule for all customers and all items ( 5% discount => priority is empty).

When i want do create a sales order for customer XYZ for a Nike shirt its gets only the 5% discount from the generally rule.

does anyone have any idea what the problem could be ???