After Purchase account activation wrong postings At MIGO

Hi Gurus,

I have activated purchase accounting today,

When only 1 accounting document is created ( separate doc not activated) then a/c posting at GR

posting key A/c Amount dr/cr

89 Spare parts 10050 dr

96 Gr/IR clearing 10000 cr

50 Freight clearing 500 cr

40 Purchase A/c 10000 dr

40 Freight Purchase A/c 500 dr

50 Purchase offset A/c 10500 cr

It seems Ok.

But when I activate to create separate accounting Doc and maintained the settings in SPRO.

now 2 documents are created but postings are.

No1. Accounting Doc

89 Spare parts 10050 dr

50 Purchase offset A/c 10500 cr

No2. purchase a/c doc

96 Gr/IR clearing 10000 cr

50 Freight clearing 500 cr

40 Purchase A/c 10000 dr

40 Freight Purchase A/c 500 dr

I copied New doc type of accounting ( for purchase ac/ doc ) from WE and create ZE. also created new number range and assigned it at MIGO/MIRO at spro

Why it is happening ?

Please help