[Samba] Poor perfomance Samba 3.0 + DBF/PX

[Sebastian Davancens]

Im running a linux fiel server with RH 8.0 and Samba,
acting as a PDC. 40 clients (Win98/2000) use an application that is 
based on Foxpro and Paradox tables, which are stored in the server 
(Contabilidad and CRT shares).
The problem is the following: with samba 2.2.8, everything worked fine. 
But when we updated to 3.0.2a, the perfomance dicreased a lot. Its really
slow. Apart from that, the .dbf files started to corrupt oftenly.
The smb.conf has not been changed.
Why is this happening??
Here i post a part of my smb.conf file:

[global]

       socket options = TCP_NODELAY IPTOS_LOWDELAY
SO_SNDBUF=8192 SO_RCVBUF=8192
    domain master = Yes
       encrypt passwords = Yes
       logon home = \\%L\%U
       server string = Samba PDC running %v
       logon script = login.bat
       veto oplock files =
/*.dbf/*.DBF/*.cdx/*.CDX/*.db/*.DB/*.Y??/*.y??/*.XG?/*.xg?/*.MB/*.mb/*.VAL/*.val/*.PX/*.px/*.mdb/*.MDB/*.lck/*.LCK/ 

       workgroup = SMBAR
       logon path = \\%L\profiles\%U
       os level = 64
       directory mask = 0770
       printcap name = /etc/printcap
       preferred master = Yes
       domain admin group = @admins
       domain logons = Yes
       log level = 1

[homes]
       comment = Home Directories
       force group = admins
       read only = No
       force create mode = 0770
       browseable = No

[profiles]
       path = /home/samba/profiles
       read only = No
       create mask = 0600
       directory mask = 0700
       browseable = No

[netlogon]
       comment = Network Logon Service
       path = /home/netlogon
       write list = @admins
       browseable = No
       browseable = No


[CRT]
       comment = CRT
       path = /home/captacion/tmkt
       admin users = @admins
       write list = @admins, @gr_crt
       force group = gr_crt
       create mask = 0775
       force create mode = 0775
       browseable = No
       dont descend = contabilidad ccvd

[contabilidad]
       comment = contabilidad
       path = /home/captacion/tmkt
       admin users = @admins
       read list = @admins, @gr_crt
       write list = @gr_contabilidad
       force group = gr_contabilidad
       browseable = No
       dont descend = crt

One last note: we have already tried with level2 oplocks = false and 
kernel oplocks = false, but it was useless
Thanks in advance,
Sebastian