Vendor Differs from PO to MIRO

Hi Experts,

Automatically PO Vendor differs from MIRO but entries are all same to the PO vendor. The accounting document generated at the time of MIGO is generated in the head of the PO vendor but the MIRO document got generated in the name of a different vendor which is automatically picked by the system The accounting entries of MIRO all are gone to that New vendor, but the amount in the PO is the same, it has been posted under the same PO Number.

Please help me.

Regards,

Arghyajit