WIP posted after TECO status and during CO88

Hi Gurus,

The Production order was created on 03-12-2012 @ 09.34.25
TECO was done on 03-12-2012 @ 09.34.25 @ 09.47.37
At month end on 31-12-2012, while doing the CO88, the system has posted as below

81 530200 PRD Variance Offset 833.17
96 530100 Production Variance 833.17

50 530010 WIP Transfer 833.17

40 11510 WIP Panel 833.17

There is production variance and so the first two line items are fine.
My question is why the system has posted WIP during the CO88 execution.

Regds

Ramachandra