Failure to install binary packages in older FreeBSD versions using “pkg_add -r”.
Solution:
Add these lines to /etc/csh.cshrc (/etc/profile if you are using bash or sh):
[FreeBSD 4.x]
setenv PACKAGESITE ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/packages-4-stable/Latest/
setenv PACKAGELIST
[FreeBSD 5.x]
setenv PACKAGESITE ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/packages-5-stable/Latest/
setenv PACKAGELIST