Why does oplocks = False not seem to stop file cacheing?

[David J. Reiter]

Greetings All,
 I have tried everything I can think of and can not seem to 
stop the PC from cacheing a local copy of a file retrieved
over a samba share. I have tried oplocks = false and also
setting veto oplocks = /*.txt/

Whatever I try the PC still shows me the old version of a file
after I modify it on the unix side. If anyone can see anything
wrong with my smb.conf file please let me know. Thanks in 
advance,

David.

; Configuration file for smbd.
; ============================================================================
[global]
  printing = sysv
  printcap name = /etc/printcap
  load printers = yes
  keepalive = 60
  guest account = nobody
  socket options = TCP_NODELAY 
  username map = /opt/samba/lib/umap
  read prediction = False
  oplocks = no
  debug level = 11
  lock directory = /opt/samba/lib/locks
  kernel oplocks = no
  ole locking compatibility = no
  share modes = yes
  locking = yes
  strict locking = yes

[pc]
   path = /NEWPC
   public = yes
   only guest = yes
   writable = yes
   printable = no
;  I have tried share modes both yes and no, that doesnt seem to
;  change anything.
   share modes = no
;  I think setting oplocks False should do the trick but it doesn't
;  seem to help.
   oplocks = False
;  So I tried to set veto to veto all files, but again this didn't
;  seem to help any.
   veto oplock files = /*.txt/