samba - Nov 2007 - Transistive problem with AD logins via winbind

Hello,

I am getting transitive problems with logins to CentOS 5 boxes via
AD/Kerberos. The winbind log is:

[2007/11/26 07:51:07, 1]
nsswitch/winbindd_pam.c:winbindd_raw_kerberos_login(571)
winbindd_raw_kerberos_login: kinit failed for 'user@TESTDOMAIN.COM'
with:
Cannot contact any KDC for requested realm (-1765328228)
[2007/11/26 07:52:14, 1]
rpc_client/cli_pipe.c:cli_pipe_validate_current_pdu(625)
cli_pipe_validate_current_pdu: RPC fault code DCERPC_FAULT_ACCESS_DENIED
received from remote machine dc1.testdomain.com pipe \lsarpc fnum 0xc000!
[2007/11/26 07:52:14, 0]
rpc_client/cli_pipe.c:cli_rpc_pipe_open_ntlmssp_internal(2362)
cli_rpc_pipe_open_ntlmssp_internal: cli_rpc_pipe_bind failed with error NT
code 0x00000005
[2007/11/26 07:52:14, 1]
nsswitch/winbindd_pam.c:winbindd_raw_kerberos_login(571)
winbindd_raw_kerberos_login: kinit failed for 'user@TESTDOMAIN.COM'
with:
Cannot contact any KDC for requested realm (-1765328228)
[2007/11/26 08:55:51, 1]
rpc_client/cli_pipe.c:cli_pipe_validate_current_pdu(625)
cli_pipe_validate_current_pdu: RPC fault code DCERPC_FAULT_ACCESS_DENIED
received from remote machine dc2.testdomain.com pipe \lsarpc fnum 0x4005!
[2007/11/26 08:55:51, 0]
rpc_client/cli_pipe.c:cli_rpc_pipe_open_ntlmssp_internal(2362)
cli_rpc_pipe_open_ntlmssp_internal: cli_rpc_pipe_bind failed with error NT
code 0x00000005
[2007/11/26 08:55:51, 1]
rpc_client/cli_pipe.c:cli_pipe_validate_current_pdu(625)
cli_pipe_validate_current_pdu: RPC fault code DCERPC_FAULT_ACCESS_DENIED
received from remote machine dc2.testdomain.com pipe \samr fnum 0x4008!
[2007/11/26 08:55:51, 0]
rpc_client/cli_pipe.c:cli_rpc_pipe_open_ntlmssp_internal(2362)
cli_rpc_pipe_open_ntlmssp_internal: cli_rpc_pipe_bind failed with error NT
code 0x00000005

Can anyone help me understand what this could be caused by? Restarting
winbind a couple of times normally resolves the problem.

Thanks.