Unable to mount CIFS NAS on >Volumio1.2

I’ve got a fully-functioning, Pi-based Volumio1.2; I’d like to try the new versions but I hit the mount fail on everything later than 1.2. Just tried the 1.55 version and the jump from wheezy to jessie, but the mount command fails again. I’ve copied the 1.2 settings to a text file and re-input them, so there’s the same starting point, I’ve gone through the apt-get upgrade/update/rpi-update cycle until there’s nothing more to be wrung out of the repositories, I’ve checked that cifs-utils is present and correct, and I’m running out of ideas. Obviously, I’ve missed something but what?

Added: For the avoidance of doubt, I’ve tried sec=ntlm, ntlmv2 and ntlmssp. The 1.2 version runs perfectly happily with ntlm…

Sort of solved… I changed the mount type from CIFS to NFS, as the Netgear NAS does both. That connected through just fine, although I still don’t know why the CIFS setup no longer works. There is a Ubuntu bug (Bug #1113395) that looks like this and as of November last year it was still extant. Other things I tried were the undocumented ‘sec=lanman’ option which had worked for some but not for me.