I had this and was advised to do this:
$ sudo modprobe cifs
$ sudo modprobe md4
$ sudo mount.cifs //192.168.101.100/sharename /mnt/mountname -o username=shareuser,password=sharepassword,domain=domainname
I also had to install cifs-utils and append lines in /etc/modules to load cifs and md4 at startup
I can now mount SMB shares on my NAS using an entry in fstab.