mail location change generates various errors

[Cliff Hayes]

I have a sendmail/dovecot imap/pop3 system that has been running with 
the following mail_location:

mail_location = 
mbox:/var/empty:INBOX=/var/spool/mail/%u:INDEX=/var/indexes/%u

In order to reduce errors and simplify operation I removed imap and am 
now only responding to pop3.  I'd like to also simplify the 
mail_location to get rid of index errors since I don't need indexes:

mail_location = mbox:/var/spool/mail:INBOX=/var/spool/mail/%n

But when I applied the new mail_location I began to get the following 
five errors:

Nov  6 23:17:24 sendmail dovecot: pop3(chayes): Warning: UIDVALIDITY 
changed (1132434125 -> 1205169149) in mbox file /var/spool/mail/chayes

Nov  6 23:17:26 sendmail dovecot: pop3(chayes): Panic: Message 
unexpectedly expunged from index

Nov  6 23:17:26 sendmail dovecot: pop3(chayes): Error: Raw backtrace: 
/usr/lib64/dovecot/libdovecot.so.0() [0x3340045e2a] -> 
/usr/lib64/dovecot/libdovecot.so.0() [0x3340045e6e] -> 
/usr/lib64/dovecot/libdovecot.so.0(i_fatal+0) [0x3340019eb3] -> 
/usr/lib64/dovecot/libdovecot-storage.so.0() [0x3ef62567ed] -> 
/usr/lib64/dovecot/libdovecot-storage.so.0() [0x3ef6256e75] -> 
/usr/lib64/dovecot/libdovecot-storage.so.0() [0x3ef62928ed] -> 
/usr/lib64/dovecot/libdovecot-storage.so.0(index_mail_set_seq+0x76) 
[0x3ef6294ae6] -> /usr/lib64/dovecot/libdovecot-storage.so.0() 
[0x3ef625698c] -> dovecot/pop3() [0x405ec7] -> 
dovecot/pop3(client_command_execute+0x6d7) [0x4071c7] -> 
dovecot/pop3(client_handle_input+0x78) [0x405618] -> 
/usr/lib64/dovecot/libdovecot.so.0(io_loop_call_io+0x36) [0x3340052c36] 
-> /usr/lib64/dovecot/libdovecot.so.0(io_loop_handler_run+0xa7) 
[0x3340053a57] -> /usr/lib64/dovecot/libdovecot.so.0(io_loop_run+0x28) 
[0x3340052778] -> 
/usr/lib64/dovecot/libdovecot.so.0(master_service_run+0x13) 
[0x334003e3c3] -> dovecot/pop3(main+0x283) [0x403cc3] -> 
/lib64/libc.so.6(__libc_start_main+0xf5) [0x359f821a05] -> 
dovecot/pop3() [0x403e2d]

Nov  6 23:17:26 sendmail dovecot: pop3(chayes): Fatal: master: 
service(pop3): child 3358 killed with signal 6 (core dumps disabled)

Nov  6 23:18:00 sendmail dovecot: pop3(jbkirk): Error: 
open(/var/spool/mail/.imap/INBOX/dovecot.index.log) failed: Permission 
denied (euid=2151(jbkirk) egid=12(mail) missing +r perm: 
/var/spool/mail/.imap/INBOX/dovecot.index.log, dir owned by 3575:12 
mode=0770)

dovecot -n output

# 2.1.16: /etc/dovecot/dovecot.conf
# OS: Linux 3.9.2-200.fc18.x86_64 x86_64 Fedora release 18 (Spherical 
Cow) ext4
auth_mechanisms = plain login
auth_verbose = yes
auth_verbose_passwords = plain
disable_plaintext_auth = no
mail_location = 
mbox:/var/empty:INBOX=/var/spool/mail/%u:INDEX=/var/indexes/%u
mbox_write_locks = fcntl
namespace inbox {
   inbox = yes
   location =
   mailbox Drafts {
     special_use = \Drafts
   }
   mailbox Junk {
     special_use = \Junk
   }
   mailbox Sent {
     special_use = \Sent
   }
   mailbox "Sent Messages" {
     special_use = \Sent
   }
   mailbox Trash {
     special_use = \Trash
   }
   prefix =
}
passdb {
   driver = pam
}
protocols = pop3
ssl = no
ssl_cert = </etc/pki/dovecot/certs/dovecot.pem
ssl_key = </etc/pki/dovecot/private/dovecot.pem
userdb {
   driver = passwd
}

What do I need to do to transition to the new mail_location without the 
errors?

Thanks in advance.