[Samba] Slow Directory Access after upgrade to 3.5.6

[Mike]

Follow-up on first post:

/var/log/samba/nmbd.log --

[2011/09/19 13:13:07.959554,  0]
nmbd/nmbd_browsesync.c:350(find_domain_master_name_query_fail)
  find_domain_master_name_query_fail:
  Unable to find the Domain Master Browser name MW<1b> for the workgroup MW.
  Unable to sync browse lists in this workgroup.
[2011/09/19 13:28:07.204633,  0]
nmbd/nmbd_browsesync.c:350(find_domain_master_name_query_fail)
root at a1:/var/log/samba#


smbclient -N -L a1 --

Anonymous login successful
Domain=[MW] OS=[Unix] Server=[Samba 3.5.6]
Sharename       Type      Comment
---------               ----         -------
Ac                     Disk
Ma                     Disk
Ca                     Disk
Ne                     Disk
Ol                      Disk
Ka                     Disk
Mz                    Disk
Fa                     Disk
Sc                     Disk
IPC$            IPC       IPC Service (A1 Server)
Anonymous login successful
Domain=[MW] OS=[Unix] Server=[Samba 3.5.6]

Server               Comment
---------            -------
A1                   A1 Server

Workgroup            Master
---------            -------
MW                   A1


/etc/samba/smb.conf --

#======================= Global Settings
=====================================
[global]

   netbios name = a1
   workgroup = mw
   server string = A1 Server
   security = user
   hosts allow = 192.168.1.  127.0.0.
   hosts deny = 0.0.0.0/0
   log file = /var/log/samba.%m
   max log size = 500
   passdb backend = tdbsam
   encrypt passwords = Yes
   local master = yes
   os level = 99
   time server = yes
   preferred master = yes
   wins support = yes
   wide links = no
#============================ Share Definitions
==============================

[Ac]
writable = yes
read only = no
guest ok = yes
public = yes
oplocks = true
level2 oplocks = true
path = /abc/def
create mask = 0777
directory mask = 0777
security mask = 0777
directory security mask = 0777


[Ma]
writable = yes
read only = no
guest ok = yes
public = yes
oplocks = true
level2 oplocks = true
path = /abc/ghi
create mask = 0777
directory mask = 0777
security mask = 0777
directory security mask = 0777

the settings on all other shares are precisely the same.