samba - Apr 2008 - Working PDC: "Initialization failed for alloc backend"

My home domain includes a Samba 3.0.28a PDC on Fedora 8, a winXP and a 
win2K machine.
It seems to be working well but I'm constantly getting the below error 
messages in the logs.

What do they mean and do I need to do anything about them?

Apr 10 18:19:18 pc100 winbindd[3063]: [2008/04/10 18:19:18, 0] 
nsswitch/idmap.c:idmap_alloc_init(750)
Apr 10 18:19:18 pc100 winbindd[3063]:   ERROR: Initialization failed for 
alloc backend, deferred!
Apr 10 18:19:18 pc100 smbd[3397]: [2008/04/10 18:19:18, 0] 
auth/auth_util.c:create_builtin_administrators(792)
Apr 10 18:19:18 pc100 smbd[3397]:   create_builtin_administrators: 
Failed to create Administrators
Apr 10 18:19:18 pc100 winbindd[3063]: [2008/04/10 18:19:18, 0] 
nsswitch/idmap.c:idmap_alloc_init(750)
Apr 10 18:19:18 pc100 winbindd[3063]:   ERROR: Initialization failed for 
alloc backend, deferred!
Apr 10 18:19:18 pc100 smbd[3397]: [2008/04/10 18:19:18, 0] 
auth/auth_util.c:create_builtin_users(758)
Apr 10 18:19:18 pc100 smbd[3397]:   create_builtin_users: Failed to 
create Users

Thanks,
Philip Pawley