I needed 1 day to understand that the shipped version of FTPd in OpenBSD 3.0 was not Heimdal compliant. After building the Heimadl0.4e one, it finally accepted the AUTH command. So if some people were interested in kerberizing their ftpd, do not the same error that I did. I have currently one problem, the FTPd cannot initialize GSSAPI. I am working on it.