Can't mount a cifs share

[Simon Andrews]

I'm trying to mount a cifs share from a RHEL5 server to a Fedora 14 
machine.  I can do this just fine if I go through the GUI in Gnome, but 
I need to be able to do this from the command line as well.  I'm sure 
I'm making a simple mistake, but I can't see it.

I can see the share I want to export (data):

$ smbclient -L servername -U username
Enter username's password:
Domain=[MYGROUP] OS=[Unix] Server=[Samba 3.0.28-0.el5.8]

         Sharename       Type      Comment
         ---------       ----      -------
         IPC$            IPC       IPC Service (Samba Server Version 
3.0.28-0.el5.8)
         data            Disk      Pipeline data
         Username        Disk      Home Directories
Domain=[MYGROUP] OS=[Unix] Server=[Samba 3.0.28-0.el5.8]

         Server               Comment
         ---------            -------
         PIPELINE             Samba Server Version 3.0.28-0.el5.8

But when I try to mount it I get:

  sudo mount -t cifs //servername/data /mnt/pipeline -o 
user=username,password=mypassword

mount: wrong fs type, bad option, bad superblock on //servername/data,
        missing codepage or helper program, or other error
        (for several filesystems (e.g. nfs, cifs) you might
        need a /sbin/mount.<type> helper program)
        In some cases useful info is found in syslog - try
        dmesg | tail  or so

The dmesg error says:

CIFS VFS: cifs_mount failed w/return code = -22

..which I thing means 'Invalid argument'?

I've tried various combinations of supplying usernames and passwords, 
but can't seem to get anywhere.

Can anyone see what I'm missing?

Cheers

Simon.