10.6x client 10.5.8 Server AFP punts

10.5x server set AFP auth to kerberos (same machine hosts OD) 10.6 clients get un/pw error. When I turn auth on server to Any Method, 10.6 clients connect without issue, thus far. Is there something else I should be changing to keep my Kerb auth on the AFP shares alive while allowing my 10.6 clients access to said shares? TIA, damon