When the LDAP USE flag is set, the Samba package requires the file ldap.h. To fix, openldap (or an equivalent?) should be emerged first; thus, a dependancy should be created.
<snip> ldap? ( kerberos? ( virtual/krb5 ) net-nds/openldap ) </snip> What's your problem?
interesting...well, when I did an "emerge -auD system" on a fresh 2006.0 stage3 install, portage must have missed this dependancy. Obviously, I have kerberos and ldap use flags set, but portage did not emerge openldap first. In any case, I'll leave as resolved until I can figure out what went wrong.