cifs WinXP problem

[Mike -- EMAIL IGNORED]

Sorry to trouble you with what may be a Microsoft problem.
On my LAN, I replaced one of my Win2k boxes with a new
WinXP box.  I use cifs to connect with MS boxes from an
FC7 box.  Here is the main part of the start script in
init.d :

case $1 in
   start)
      mount -t cifs -o user=administrator%
xxx,noauto,suid,dir_mode=0700,file_mode=0700 //abcd30/base /mnt/base30
      mount -t cifs -o user=administrator%
xxx,noauto,suid,dir_mode=0700,file_mode=0700 //abcd10/mike_local /mnt/
mike_local_10

abcd30 is a Win2k box.
abcd10 is the new WinXP box; mike_local is a share name on a directory.

abcd30 connects correctly; for abcd10 I get:

# smb start
mount error 5 = Input/output error
Refer to the mount.cifs(8) manual page (e.g.man mount.cifs)

The man page says little of errors.  I note that: ping works fine;
the new box and its shared directory are visible from other Win
boxes; the real passwords are the same on both boxes and have no
inappropriate characters.  I tried shutting down iptables and
ZoneAlarm (with WAN disconnected, of course).

Thanks for your help.
Mike.