title: 2 invoices generated for order. Order is canceled before payment
body: <p>I have following problem:</p>
  
  <p>We are running webshop and sometimes it happens that 2 invoices are generated for 1 order. </p>
  
  <p>Moreover sometimes order gets canceled before even customer goes to payment-gateway.</p>
  
  <p>I'v united those 2 questions, because I think they have some similar reason and perhaps some similar solution.</p>
  
  <p>Our magento version is 1.5.1.0.</p>