apt-get newbie question

[<michael@yoon.org>]

Hi,

I decided to upgrade my slink box to potato tonight, using apt-get
(0.3.10) for the first time, but I've gotten stuck:

My /etc/apt/sources.list consists of one line:

	deb http://http.us.debian.org/debian unstable main contrib non-free

I first ran "apt-get update", which seemed to work fine.

Then, I ran "apt-get -f dist-upgrade", which is where things went
awry: apt-get appeared to download a good number of packages
successfully before coughing up 404 Not Found errors for dpkg-ftp,
lilo, dhcpcd, gdb, info, man-db, libgpmg, gpm, dhcpcd, and
nfs-server. Then, apt-get just quit, suggesting I try --fix-missing.

So I believe I understand what the 404 errors mean -- the files that
apt-get is trying to get simply don't exist -- but what I don't
understand is if I'm doing something wrong that's causing these
errors.

Am I correct in assuming that the Packages list created by "apt-get
update" is somehow out of sync with what's actually on
http.us.debian.org? Or is there something else I'm missing? More to
the point, what can I do to workaround this problem? Try another
mirror?

Thanks in advance,
Michael