Is JCIFS incompatible with windows 2008 R2 domain controllers?
JCifs is abandoned. If you need NTLM2, you may migrate to commercial solution for $250 (or $500 unlimited): http://www.ioplex.com/jespa.html, or free, an NTLM part taken out from Liferay: http://sourceforge.net/projects/ntlmv2auth/. NTLM is being abandoned (mainly because of security vulnerabilities). Maybe you could migrate to Kerberos?