NTLMv2 Problem

[Chris Berry]

    I'm tightening my security and as part of that process I changed our 
domain group policy to allow NTLMv2 only.  Works fine except for one 
problem, when in this mode I can't join new computers to the domain.  It 
keeps telling me I have a bad username/password.  When I set it back to LM 
& NTLM then I can join no problem.  I tried setting the new workstation 
local policy to NTLMv2 also but that didn't help.  Looked on google but 
didn't see anything relevant, anyone have an idea of what's going on?