This patch avoids several silly warnings, and fills $res->status_line with something useful 
in case your FTP server babbles some text message without a leading response code.
Seen from ftp.opensuse.org:
connect(3, {sa_family=AF_INET, sin_port=htons(21), sin_addr=inet_addr("195.135.221.134")}, 16) = 0
read(3, "This server is busy, please try again later or any of my mirrors: http://download.opensuse.org\n\n", 1024) = 96
Note the missing "500 " before "This".
Command line ftp clients handle this gracefully, so should we.

With this patch, LWP clients see a status_line of "500 This server is busy, ..."
2006-12-20, jw@suse.de

--- perl-5.8.8/lib/Net/FTP.pm.orig	2006-12-20 21:09:01.075906000 +0100
+++ perl-5.8.8/lib/Net/FTP.pm	2006-12-20 21:09:17.324643000 +0100
@@ -119,7 +119,7 @@
  unless ($ftp->response() == CMD_OK)
   {
    $ftp->close();
-   $@ = $ftp->message;
+   $@ = $ftp->message || $@;	# keep @$ if no message. Happens, when response did not start with a code.
    undef $ftp;
   }
 
@@ -1107,7 +1107,7 @@
 sub response
 {
  my $ftp = shift;
- my $code = $ftp->SUPER::response();
+ my $code = $ftp->SUPER::response() || 5;	# assume 500 if undef
 
  delete ${*$ftp}{'net_ftp_pasv'}
     if ($code != CMD_MORE && $code != CMD_INFO);
@@ -1122,9 +1122,11 @@
 
  my $ftp = shift;
 
+
  # Darn MS FTP server is a load of CRAP !!!!
+ # Expect to see undef here. 
  return ()
-	unless ${*$ftp}{'net_cmd_code'} + 0;
+	unless 0 + (${*$ftp}{'net_cmd_code'}||0);
 
  (${*$ftp}{'net_cmd_code'},1);
 }
--- perl-5.8.8/lib/Net/Cmd.pm.orig	2006-12-20 21:09:05.850129000 +0100
+++ perl-5.8.8/lib/Net/Cmd.pm	2006-12-20 21:09:17.332631000 +0100
@@ -338,9 +338,11 @@
      if ($cmd->debug);
 
    ($code,$more) = $cmd->parse_response($str);
+
    unless(defined $code)
     {
      $cmd->ungetline($str);
+     $@ = $str;		# $@ is used as a tunneling hack.
      last;
     }
 
@@ -351,6 +353,7 @@
    last unless($more);
   } 
 
+ return undef unless defined $code;
  substr($code,0,1);
 }