Overall release strategy for purchase requisition not rigth determinated

Hello!

We are using overall release strategy since 4 years ago and this is the first case we have.

We installed EHP6 3 months ago (April 2013).

This is the case:

A Requisition with 2 items different cost center has been created, when save it, the release strategy is not the correct one. It is taking release strategy 01 instead Release strategy 04.

We already check CL24N and both cost centers are in the same release strategy.

if we create individal requisitions per cost center we got the right release strategy but when use together isn't.

This was not happening in the past.

Release group in IMG is set as overallRelease.

Our Class is as follow:

ACCOUNT_ASSIGNMENT CEBAN-KNTTP

PLANT CEBAN-WERKS

CSTCENTER CEBAN-KOSTL

ORDER_TYPE CEBAN-USRC1

TOTAL_VALUE CEBAN-GFWRT

Our Clasifffication in CL24N is right defined.

Release strategy 01 is defined as follow (this is the one that is not correct one and PR defined).

Account Assignment Category K

Plant 7401

Cost Center 0000011010

Cost Center 0000011011

Cost Center blank

Order Type

Total value of requisition 0.01 - 1000.00 USD

Release strategy 04 is as follow (this is the one that MUST be determinated since we are using those Cost Center in the requisition):

Account Assignment Category K

Plant 7401

Cost Center 0000014655

Cost Center 0000014689

Cost Center blank

Order Type

Total value of requisition 0.01 - 1000.00 USD

I dont know why is taking the correct one!.

Additional info, if we create a requisition using just 1 line item for the Cost center 14655 and other requisition for Cost center 14689, the system select the correct release strategy, the 04.

Please any tip will be appreciated.