Stored outline not being used -- UNNEST hint?

Anynone knows if Oracle stored outline does not work with UNNEST hint is used?  I have a SQL which is like this:

SELECT /*+ index (msi MTL_SYSTEM_ITEMS_B_U1) index (ohqmv MTL_ONHAND_QUANTITIES_N4) */ AU.USER_ID ,
....
AND EXISTS ( SELECT 1 FROM CSM_INV_LOC_ASS_ACC ILAACC1, CSP_INV_LOC_ASSIGNMENTS ILA1, CSP_SEC_INVENTORIES CSI WHERE ILAACC1.USER_ID = AU.USER_ID AND ILAACC1.CSP_INV_LOC_ASSIGNMENT_ID = ....

We changed it to this below and casted the stored ouline for it:

SELECT /*+ FIRST_ROWS */ AU.USER_ID ,
....
AND EXISTS ( SELECT /*+ UNNEST */ 1 FROM CSM_INV_LOC_ASS_ACC ILAACC1, CSP_INV_LOC_ASSIGNMENTS ILA1, CSP_SEC_INVENTORIES CSI WHERE ILAACC1.USER_ID = AU.USER_ID AND ILAACC1.CSP_INV_LOC_ASSIGNMENT_ID = ....

Somehow this particular stored outline is not used by Oracle.  We are on 9206 version.  I think I read somewhere before that certain Hints would invalidate that stored oulines and may be UNNEST is one of those hints.

Thanks for any help.