NTLM connection pinning (passthrough) not working on squid 3.1.20

[John/SML <john@xxxxxxxxxxxxxxxxx>]

Hi,

When I upgraded from squid 2.7 to squid 3.1 on Debian 7.1.0, it is found 
that the NTLM connection pinning (NTLM passthrough) not working any 
longer. 

I hope someone could inform the status of NTLM connection pinning, whether 
I should upgrade to 3.3 or downgrade to 2.7.

Thanks a lot.

John Mok