Sales Order Error

HI,

In a particuar sales order, document flow is completed till Post Goods Issue.

But in document flow, for sales order the status is shown as 'Being Processed'; Delivery : Being Processed; Picking : Completed; Post Goods Issue : Completed.

Hence i am not able to create a Billing document for the same.

Main issue is if i go in VA03/02 for this particular sales order, system displays the message as : "Item does not match schedule line (program error)"

Message no. V1427. Hence i am not able to check this order in the system.I have checked VBAP and VBEP table status for this Sales order and found no difference in it.

Let me know if anybody has any idea on the same.

-Sachin D