samba - Jan 2008 - Samba hangs DOS apps (foxpro and clipper)

Hi.
I start to manage small network with about twenty
workstation. There is an old DELL with Novell 3 as file server
and spooler for four printers. Clients (Win98 and WinXP)
runs dos applications written in clipper and foxpro.
Everything works fine, but... :)
I want to migrate file server and spooler in to new server
with RHEL5. Cups works fine, but Samba not. DOS apps
randomly hangs or freeze for few sec. without any any reason.
Someone told me to try Samba 2.2.8a and reedit smb.conf
I turning off "read/write raw" also change "blocking locks",
"locking", "kernel oplocks" and "strict locking"
options.
Now frequency of hangs is smaller then before, but it's still.
Anyone help?

PS. Sorry for my english.

[global]
#        unix charset = UTF8
#        character set = UTF8
        client code page = 852
        netbios name = serwer
        server string = serwer
        workgroup = TBS
        security = user
        encrypt passwords = yes
        kernel oplocks = no
        interfaces = 10.1.1.253/24, 127.0.0.1
        bind interfaces only = yes
        socket options = TCP_NODELAY SO_SNDBUF=8192 SO_RCVBUF=16384 
IPTOS_LOWDELAY
        read raw = no
        write raw = no
        getwd cache = no
        preserve case = yes
        max open files = 1000
        guest account = pcguest
        level2 oplocks = no
        oplocks = no
        veto oplock files = /*.DBF/*.dbf/*.CDX/*.cdx/*.STX/*.stx
        blocking locks = no
        locking = yes
        strict locking = yes
        username map = /usr/local/samba/private/smbusers
        log level = 2
        log file = /var/log/samba/%m.log
        max log size = 50
        time server = Yes
        logon script = %U.bat
        logon path         logon home         domain logons = Yes
        os level = 255 
        preferred master = Yes
        domain master = Yes
        dns proxy = No
        wins support = Yes
        load printers = yes
        printing = cups
        printcap name = cups
#        cups options = raw
        keep alive = 10
        dead time = 5

[homes]
        comment = Home Directories
        valid users = %U
        read only = No
        browseable = No

[netlogon]
        comment = Network Logon Service
        path = /usr/local/samba/lib/logon
        guest ok = Yes
        browseable = No
        share modes = No

[D2]
        path = /var/samba/D2
        valid users = @samba, root
        read only = No
        force create mode = 770
        create mask = 0770
        directory mask = 0770
        dos filetime resolution = Yes
        dos filetimes = yes

[D3]
        path = /var/samba/D3
        read only = No
        create mask = 0770
        directory mask = 0770
        dos filetime resolution = Yes

[BETA]
        path = /var/samba/D2/PRZELEW/BETA
        valid users = root, @przelew
        write list = root, @przelew
        read only = No
        create mask = 0770
        directory mask = 0770
        dos filetime resolution = Yes

[SYS]
        path = /var/samba/SYS
        valid users = root, @samba
        write list = @root
        read only = No
        create mask = 0755
        dos filetime resolution = Yes

[OKI3321]
        comment = OKI3221 w serwerowni
        path = /var/spool/samba
        printer name = OKI3321
        public = yes
        guest ok = yes
        printable = yes
        writable = no
        use client driver = yes

[HP1200]
        comment = HP1200 w ksiegowosci
        path = /var/spool/samba
        printer name = HP1200
        public = yes
        guest ok = yes
        printable = yes
        writable = no
        use client driver = yes

[HP2015]
        comment = HP2015 w ksiegowosci
        path = /var/spool/samba
        printer name = HP2015
        public = yes
        guest ok = yes
        printable = yes
        writable = no
        use client driver = yes