Oracle 8.1.7.3.50 EE, MVS, OS3/90 Z/OS

Hi
In Production after rebuild of partitioned indexes we have some bad execution-plans. Now i want to take the good working Executuin-plans from another instance.

Steps

Instance 'good' :
* give application-user create any outline -Sys-priv
* create the outlines from the SQL in V$sql of the 'bad' instance

export the outln-tables

Instance 'bad'
* give application-user create any outline -Sys-privs
* alter the system : use_stored_outlines = TRUE
* import the outln-tables from good db
* flush the shared_pool


But on 'bad' instance :
select * from user_outlines show still 'UNUSED'
in v$sql the columns OUTLINE_CATEGORY is still NULL

What i have do wrong?
both instances are the same Version
the *enabled-init.ora is the same

Orca