In a previous thread I was trying to set up a new firewall with
OpenBSD 3.5 (in place of FreeBSD). After setting up the firewall and
using for a week, I found that ftp just did not work.

After some googling, I finally found that in addition to enabling
ftp-proxy, I had to configure the packet filtering correctly.

More details at the OpenBSD for Dummies webpage.

www.svgeek.com/dummies/opendummies.html

Purists will probably object to rebooting the system at the end of the
changes, but I found it worked better for me (probably had to flush
the caches or something).

Ben