[Samba] Mac OS X client problem with supplementary groups

[Gordon Grant]

I have a very simple Samba 3.0.1 install without LDAP/ADS/winbind 
support compiled into it.  I have noticed a strange problem with 
supplementary groups I noticed with Mac OS X (10.3.2).  The SAMBA 
server is using 'ntdomain' authentication.

When someone connects to the SAMBA server and gives their username in 
uppercase (the OS's default), then none of the secondary UNIX groups 
the user is a member of is picked up.  If exactly the same connect is 
made, but with the username in lowercase, then the groups are picked 
up.

I have verified this in debug logs (can post) -- this seems v. odd to 
me, surely I must be missing something here??