Posting Payment Error

Hi everybody, I need your help on this thing, maybe it’s simple for you. After import demo data into Axapta, I create a new Customer, called “c1”. then create a new sales order for this customer “c1”.–> post to Invoice, called “inv1” Then I try to create a payment for this invoice by: create a customer payment journal. go to line, payment proposal, proposal by due date. i can choose the invoice “Inv1” But everytime I try to post the payment journal, Axapta complain that: “The transactions on voucher ‘00008_CPA’ do not balance as per ‘16/03/2006’. (Company currency: -1,08 - secondary currency: )” Thanks for your help