Given the simple Samba (v3.0.23a) smb.conf below on an AIX (4.3.2)
server which has been successfully joined to our domain

Why would a DOS command on a client PC such as: << dir \\server\user1
>> fail intermittently?

# Samba v3.0.23a
workgroup = MYDOM
server string =
security = DOMAIN
passdb backend = tdbsam
username map = /usr/local/samba/lib/

read only = No

Setting SO_KEEPALIVE, deadtime=0 and keepalive=0 have no effect.
The intermittent failures also occurred with security=SERVER, before
joining to the domain.