Shopping cart created with two PO's for one line item

Hi Experts,

We are using SRM 7.13 classic scenario with self service procurement, for one of the user we are getting a peculiar issue:

1) Shopping Cart created in SRM.

2) PO created in the back end.

3) But the PO is reflecting in SRm is different.

4) the PO that is appearing in the SRM is not generated in Backend i.e., ECC system.

5) The PO created in the backend is not appearing in SRM system.

6) Now that SC is in error in transmission.

7) I checked the XML messages in SRM and ECC  the PO which generated in the back end is appearing in XML file not the PO that is showing in SRM system.

Now User raised why 2 POs have been generated.

Please help me out in resolving it , why this has been occured. Please provide any table name that has been holding this one.

Thanks & Regards,

Pramod.