Here is a trick I use a couple of times a month to get finicky compute nodes in a Apple compute clusters to correctly bind to their LDAP / Open Directory master. This started working as of OS X 10.4, and to my knowledge it still works as of OS X 10.6.1.
Bioteam uses a pretty standard architecture, where the portal has the IP address and domain settings below. Modifying those for your particular setup is left as an exercise for the reader.
ldapsearch -h 192.168.2.254 -b "dc=cluster,dc=private" -x
slapconfig -setldapstatic 192.168.2.254
Apple’s “Directory Utility” GUI app is great, but for cluster maintenance you really can’t beat the command line.