Mysql replicate-rewrite-db not working

Been "slaving" on this issue all day.

I have a master/slave setup that works, but when I try to replicate to a different database name on the slave it fails. This is what my.cnf looks like:

server-id=101
report-host=Slave01

replicate_do_db='DB1'
replicate-rewrite-db=DB1->DB2

replicate-ignore-table=DB2.SOME_TABLE_NAME

If I take out the replicate-rewrite-db line, it works perfectly and replicates the DB1 database from the master to the slave. The master log position I am using on the slave is after the CREATE DATABASE DB1 call on the master. After that log position, the tables are created and data imported on the master. I don't configure and start the slave until after I create the DB2 database.

Any ideas?

Update: Saw this in the mysql error log:

120531 15:48:19 [Note] Slave I/O thread: connected to master 'slave_user@master_server:3306',  replication started in log 'mysql-bin.000001' at position 107
120531 15:48:20 [ERROR] Slave: Error 'Unknown database 'DB1'' on query. Default database: 'DB1'. Query: 'CREATE TABLE `ANOTHER_TABLE` (

I received a hint in a comment but the user has since deleted it.

The trick is to not use replicate-do-db and only use replicate-rewrite-db:

#replicate_do_db='DB1'
replicate-rewrite-db=DB1->DB2

Commenting out the replicate_do_db line in my.cnf fixed it for me.

Thanks to the mystery user who pointed me in the right direction, whoever you are.