IFolder 2.1, Netware 6.5 SP5, eDirectory

I've set up three User LDAP servers, all in the one tree, thinking that it
would provide redundancy in continuing to be able to log in even if LDAP was
down on one or two servers.

IFolder admin status shows that all three User LDAPs are up and ok.

Unfortunately, if the "Global Setting" LDAP server is not reachable, users
can't log-in to iFolder anyway.

Is there something I'm missing? Are the User LDAP servers only useful for
multiple tree setups?