Help with CTM

[Shawn Kennedy]

I've been going over the man pages and the FreeBSD handbook
for a few days and am stuck as to what my problem is.

I've used cvsup for a few years until my company killed
access through the firewall. Last recourse is CTM.
I found the CTM files and FTP'ed them down to
the box.  I ran what I thought was the appropriate 
command:

cd /usr/ports
ctm -v -v /usr/ctm/ports/ports-cur.5000xEmpty.gz

I received that the .ctm_status file didn't exist 
(assumed that - first time it's running) but it said
that all the files in the list exist (I am assuming it's
because I've last cvsup'ed about 1 month ago). Error code
returned is 80.

I thought that I would now try and run the next file in
sequence, but it failed!

The first file it tried to edit was Mk/bsd.sites.mk
and it said the md5 didn't match and gave me an exit code 104.
Also said the .ctm_status file wasn't found.

What in the world am I doing wrong?  Is it because I didn't blow
away /usr/ports first?

Shawn Kennedy