Index Rebuild Compute Statistics option in Oracle Enterprise

[jreddy]

We have jobs that have the Oracle Stage (target) that are in truncate-insert mode and have the index mode = Rebuild and the Add compute Statistics option set to true.

Normally in production, we have the stats on the tables locked and can be only analyzed using the dbms package statements (with the force option). When we had the database as Oracle 10g, these jobs did not error out even when the stats are locked. We recently upgraded our application databases to 11g and DS to V8.1 from V7.5 , when these jobs started throwing errors

"aptoci.C:355). Message: ORA-38029: object statistics are locked"

My question is why didnt the jobs aborted with similar error in 10g/V 7.5 but did so in 11g/V8.1 ? Would this be some setting on DS perhaps?
Also, what does this Add COMPUTE STATISTICS option do at the backend - does it run a analyze statement or the dbms package for gather stats ?

Thanks