Switch to Auto-Grouped backup yeilds "operation sent to wrong host"

[peter@mxtoolbox.com]

I have two servers and when I switched to Auto-Grouped backups from the old style, I get errors like below. This was thrown on a backup of zim1.host.com.

user@domain.com: operation sent to wrong host (you want 'zim2.host.com')
com.zimbra.common.service.ServiceException: operation sent to wrong host (you want 'zim2.host.com')
ExceptionId:FullBackupThread:1238979633648:8a91afa6a1618790
Code:service.WRONG_HOST Arg:(host, STR, "zim2.host.com")
        at com.zimbra.common.service.ServiceException.WRONG_HOST(ServiceException.java:295)
        at com.zimbra.cs.mailbox.MailboxManager.getMailboxById(MailboxManager.java:394)
        at com.zimbra.cs.mailbox.MailboxManager.getMailboxByAccountId(MailboxManager.java:273)
        at com.zimbra.cs.mailbox.MailboxManager.getMailboxByAccountId(MailboxManager.java:244)
        at com.zimbra.cs.backup.BackupSet.startFullBackup(BackupSet.java:352)
        at com.zimbra.cs.backup.FileBackupTarget$FileBackupSet.startFullBackup(FileBackupTarget.java:815)
        at com.zimbra.cs.backup.BackupManager.doBackupFull(BackupManager.java:729)
        at com.zimbra.cs.backup.BackupManager$FullBackupThread.run(BackupManager.java:218)

Here is more information about the mailbox from zmprov

[zimbra@zim1 ~]$ zmprov ga user@domain.com| grep zim1
[zimbra@zim1 ~]$ zmprov ga user@domain.com| grep zim2
zimbraMailHost: zim2.host.com
zimbraMailTransport: lmtp:zim2.host.com:7025

If I try to do this

zmmailboxmove -a user@domain.com -po -s zim1.host.com

I get "Error occurred: system failure: Account user@domain.com does not have an old mailbox to purge." But if I run the following commands, the error does go away

zmmailboxmove -a user@domain.com -ow -s zim2.host.com -t zim1.host.com 
zmmailboxmove -a user@domain.com -po -s zim2.host.com 
zmmailboxmove -a user@domain.com -ow -t zim2.host.com -s zim1.host.com 
zmmailboxmove -a user@domain.com -po -s zim1.host.com

Any idea how I can clear up my machine's confusion without moving the mailbox back and forth?

Thanks,
Peter