I don't believe this is a problem with ncftp itself (I'm
running ncftp-3.0beta9-1), but rather with the
ftp.redhat.com site.

I have a script that uses ncftpls and ncftpget to grab the
latest files
from ftp.redhat.com/rawhide/i386/RedHat/RPMS.  I have
been using this script successfully for quite a while, but
it failed today.  I ran the
script several times this morning, using two different ISPs
(TCI@Home and SGI).  With each ISP, my first run of the
script accessed what appeared to be an up-to-date version of
ftp.redhat.com/rawhide/i386/RedHat/RPMS, but when the script
attempted to retrieve some of the files, ncftpget returned
error 3 (transfer failed) on about half of the files  The
other half of the files were retrieved successfully.  The
transfer failures occurred in an alternating pattern -- if
one transfer succeeded, the next one would fail, and the
next one would succeed, etc.

With each ISP that I tried, subsequent runs of my script
after the first accessed what appeared to be an out-of-date
version of ftp.redhat.com/rawhide/i386/RPMS.  Most of the
packages appeared in older versions; e.g. on the first run
ncftpget picked up kernel-2.2.10-3, but on subsequent runs
ncftpget picked up kernel-2.2.5-25.  When I tried ncftp in
interactive mode and did an ls, I saw the older versions.

Perhaps there is some sort of route-flapping going on
between multiple ftp.redhat.com servers, or a load
balancing mechanism that is selecting between multiple
servers that aren't in sync with each other?

For completeness, here is the script:

#!/bin/bash
buildtime() {
    rpm -q --queryformat '%{BUILDTIME}' $*
}
rpmget() {
    echo -n "opening ftp://$1/: "
    files=$(ncftpls ftp://$1/); ret=$?
    if [ $ret -ne 0 ]; then
        echo ERROR ncftpls returned $ret
        return
    fi
    echo ok
    for file in $files; do
        echo -n "$file: "
        pkg=${file%-*-*}
        pkgver=${file%.*.rpm}
        if [ ${file##*.} != rpm ]; then
            echo skipping
        elif ! eval rpm -q $pkg &> /dev/null; then
            echo pkg not installed
        elif eval rpm -q $pkgver &> /dev/null; then
            echo pkg already installed
        elif [ -f ./$file -o -f ../krpm/$file -o -f
../orpm/$file ]; then
            echo already downloaded
        else
            oldfile=
            for f in ./$pkg-[0-9]* ../krpm/$pkg-[0-9]*; do
                fp=${f##*/};fp=${fp%-*-*}
                if [ -f $f -a $fp = $pkg ]; then
                    oldfile=$f
                    break
                fi
            done
            ncftpget ftp://$1/$file &> /dev/null; ret=$?
            if [ $ret -ne 0 ]; then
                echo ERROR ncftpget returned $ret
            elif ! eval rpm -K --nopgp $file &> /dev/null;
then
                echo ERROR checksig failed
                rm -f $file
            elif [ $(buildtime -p $file) -lt $(buildtime
$pkg) ]; then
                echo older version
mv $file ../orpm
            else
                echo NEW
                if [ ${pkg%%-*} = kernel ]; then
                    mv $file ../krpm
                fi
                if [ -f ./$oldfile ]; then mv $oldfile
../orpm; fi
            fi
        fi
    done
}
cd /1/pkg/rpm
{
    rpmget ftp.falsehope.com/pub/Mesa/rh6.0
    rpmget ftp.falsehope.com/pub/socks5
    rpmget ftp.redhat.com/rawhide/i386/RedHat/RPMS
    rpmget ftp.redhat.com/rawhide/powertools/i386
    rpmget ftp.redhat.com/redhat/updates/6.0/i386
} 2>&1 | tee /1/pkg/getrpm.log