Why dont you try :
limits dn.exact="uid=syncrepl,ou=System,dc=example,dc=com" size=unlimited time=unlimited
As a test on the provider, maybe your group is not being expanded as you expect.
Group syntax seen elsewhere in this list have looked is more like :
limits group/groupOfUniqueNames/uniqueMember="cn=LDAPAdmins,ou=Groups,dc=example,dc=com" size=unlimited time=unlimited
I'd suggest trying the test again with the dn.exact one first, and if that works then try the other.
-- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/