I am setting up a client with Purchase Order 8.1C (20130913). I want to use Auto numbering for purchase orders. For the item number format I used PO-XXXXXX. I selected the Auto Numbering option, segment to increase is 2, next purchase order is 1, length is 8, maximum increase is 999999, next requisition is 0

When I create a Purchase Order the default number that comes up is -000001
I can edit it to put the PO in front but I don't want to do this every time.
What am I doing wrong?