Hi Ravindra,
You mean to say new order is getting created, or the current TECO status is getting reversed !! I believe new order is getting created after MRP.
If the sales order is not complete and open quantity is present, then MRP will generate new planned orders for the same. Please analyze the MD04 screen and come back. You can ask the sales guys to complete any such sales orders and run mrp to check the same.
Thanks
Prem