Windows SMB users cannot connect to 10.5.4 server

Hi all, Have a server running 10.5.4 bound to AD and running an OD to provide management of the Macs. Pretty standard setup and haven't had any problems elsewhere with the same deployment. However we're having a problem with XP users connecting to SMB shares. Mac users can connect over AFP or SMB fine, XP users are getting a "Network path could not be found" error. What's more the errors in the SMB log on the server aren't too descriptive. We're getting a few broken pipe errors, but no indication of what's causing that. XP machines don't appear to be getting to the authentication stage. Here is a section of the logs, I was initially thinking that it was some kind of problem with the name resolve order settings causing a time out (the "client 0.0.0.0 Broken Pipe" errors) but I've changed the order of the lookups around and it hasn't made any difference. The "Failed to create users" error seems likely to be as a result of me prodding the server as it only started appearing recently and would (I assume) affect Mac OS X based SMB users as well. [code][2008/09/15 16:27:29, 0, pid=93908] /SourceCache/samba/samba-187.7/samba/source/auth/auth_util.c:create_builtin_users(758) create_builtin_users: Failed to create Users [2008/09/15 16:27:30, 0, pid=93908] /SourceCache/samba/samba-187.7/samba/source/lib/util_sock.c:get_peer_addr(1224) getpeername failed. Error was Invalid argument [2008/09/15 16:27:30, 0, pid=93918] /SourceCache/samba/samba-187.7/samba/source/lib/util_sock.c:set_socket_options(261) Failed to set socket option SO_KEEPALIVE (Error Invalid argument) [2008/09/15 16:27:30, 0, pid=93918] /SourceCache/samba/samba-187.7/samba/source/lib/util_sock.c:set_socket_options(261) Failed to set socket option TCP_NODELAY (Error Invalid argument) [2008/09/15 16:27:30, 0, pid=93918] /SourceCache/samba/samba-187.7/samba/source/lib/util_sock.c:get_peer_addr(1224) getpeername failed. Error was Invalid argument [2008/09/15 16:27:30, 0, pid=93918] /SourceCache/samba/samba-187.7/samba/source/lib/util_sock.c:write_data(562) write_data: write failure in writing to client 0.0.0.0. Error Broken pipe [2008/09/15 16:27:30, 0, pid=93918] /SourceCache/samba/samba-187.7/samba/source/lib/util_sock.c:send_smb(761) Error writing 4 bytes to client. -1. (Broken pipe) [2008/09/15 16:47:38, 0] /SourceCache/samba/samba-187.7/samba/source/smbd/server.c:main(890) smbd version 3.0.25b-apple started. Copyright Andrew Tridgell and the Samba Team 1992-2007 [2008/09/15 16:47:42, 0, pid=93990] /SourceCache/samba/samba-187.7/samba/source/auth/auth_util.c:create_builtin_users(758) create_builtin_users: Failed to create Users [2008/09/15 16:47:46, 0, pid=93990] /SourceCache/samba/samba-187.7/samba/source/auth/auth_util.c:create_builtin_users(758) create_builtin_users: Failed to create Users [2008/09/15 16:47:46, 0, pid=93994] /SourceCache/samba/samba-187.7/samba/source/auth/auth_util.c:create_builtin_users(758) create_builtin_users: Failed to create Users [2008/09/15 16:47:46, 0, pid=93994] /SourceCache/samba/samba-187.7/samba/source/rpc_server/srv_pipe.c:api_rpcTNP(2287) api_rpcTNP: wkssvc: WKSSVC_NETWKSTAENUMUSERS failed. [2008/09/15 17:50:21, 0] /SourceCache/samba/samba-187.7/samba/source/smbd/server.c:main(890) smbd version 3.0.25b-apple started. Copyright Andrew Tridgell and the Samba Team 1992-2007 [2008/09/15 17:51:02, 0, pid=94197] /SourceCache/samba/samba-187.7/samba/source/rpc_server/srv_pipe.c:api_rpcTNP(2287) api_rpcTNP: wkssvc: WKSSVC_NETWKSTAENUMUSERS failed.[/code] Server is an Xserve with a Promise RAID, shares are on a 4TB partition, bound to AD (OD not running Kerberos). SMB setup seems to be correctly aware of the AD. Anyone any ideas? Thanks!