I installed a 2.2 server to test replication management with 3.0 servers. When I installed a 3.0 replica a failure was reported:

[24/30]: enabling S4U2Proxy delegation
ipa : CRITICAL Failed to load replica-s4u2proxy.ldif: Command '/usr/bin/ldapmodify -v -f /tmp/tmpWhqf7k -H ldap://pinto.example.com:389 -x -D cn=Directory Manager -y /tmp/tmpXcE42y' returned non-zero exit status 32

Due to this:

add memberPrincipal:
cifs/pinto.example.com@EXAMPLE.COM
modifying entry "cn=ipa-cifs-delegation-targets,cn=s4u2proxy,cn=etc,dc=example,dc=com"

2012-08-29T13:15:24Z DEBUG stderr=ldap_initialize( ldap://pinto.example.com:389/??base )
ldap_modify: No such object (32)

There is no cifs principal.

Alexander suggested we could resolve this by using a group for s4u2proxy instead of directly adding principals.