Sales Orders orderstatus change Purchase Order creation

Hi,

I created a Suitlet that Approves Sales Orders by simply changing the 'orderstaus' = 'B' (pending approval). This was working perfectly in the way that the Sales Order status changed to "Pending Approval" and the back-to-back Purchase Order was created automatically as it was a Dropship item. Nothing has changed since, but now the status of the Sales Order changes and no Purchase Order is created. As a test I used the standard Approve button on the Sales Order and it still works fine and a Purchase Order is created. So I do not suspect a custom script blocking anything.