jcifs-1.3.17: jcifs.smb.SmbException: Signature verification failed.

Hi experts,

I try to use Liferay 6.0.5 NTLM authentication with a 'user account' and
get the following exception from jCIFS (replaced the bundled jcif.jar with
version 1.3.17).

Caused by: jcifs.smb.SmbException: Signature verification failed.
        at jcifs.smb.SmbTransport.checkStatus(SmbTransport.java:548)
        at jcifs.smb.SmbTransport.send(SmbTransport.java:645)
        at jcifs.smb.SmbSession.send(SmbSession.java:244)
        at jcifs.smb.SmbTree.send(SmbTree.java:119)
        at jcifs.smb.SmbFile.send(SmbFile.java:770)
        at jcifs.smb.SmbFile.open0(SmbFile.java:982)
        at jcifs.smb.SmbFile.open(SmbFile.java:999)
        at jcifs.smb.SmbFileOutputStream.<init>
(SmbFileOutputStream.java:142)
        at
jcifs.smb.TransactNamedPipeOutputStream.<init>
(TransactNamedPipeOutputStream.java:32)
        at jcifs.smb.SmbNamedPipe.getNamedPipeOutputStream
(SmbNamedPipe.java:187)
        at jcifs.dcerpc.DcerpcPipeHandle.doSendFragment
(DcerpcPipeHandle.java:68)
        at jcifs.dcerpc.DcerpcHandle.sendrecv(DcerpcHandle.java:181)
        at jcifs.dcerpc.DcerpcHandle.bind(DcerpcHandle.java:126)
        at
com.liferay.portal.security.ntlm.NetlogonConnection.
connect(NetlogonConnection.java:73)
        at com.liferay.portal.security.ntlm.Netlogon.logon(Netlogon.java:54)

Server-side: Windows Server 2003, LAN Manager authentication level is set to
default ('send NTLM response only').

Liferay is doing the following ...

NtlmPasswordAuthentication ntlmPasswordAuthentication =
 new NtlmPasswordAuthentication(
	null, ntlmServiceAccount.getAccount(),
	ntlmServiceAccount.getPassword());

	String endpoint = "ncacn_np:" + domainController + 
                          "[\\PIPE\\NETLOGON]";

	DcerpcHandle dcerpcHandle = DcerpcHandle.getHandle(
			endpoint, ntlmPasswordAuthentication);

	setDcerpcHandle(dcerpcHandle);

	dcerpcHandle.bind();

Network trace can be provided.

Thanks a lot for any pointers.

Rgds,
Bernhard