[Samba] Windows Explorer hangs when clicking on a samba share

[tacallah at insb.uscourts.gov]

I am new to samba and Linux.  I mapped a drive from my Windows XP 
workstation to the /opt directory on the Linux box.  When I am in Windows 
Explorer and I am viewing the samba drive, I can click on any directory or 
file on that drive, and the speed is very fast (like a local drive).  If I 
click on another drive and click on the samba drive again after five 
minutes or so, my workstation hangs for about 15 seconds until the 
directories from the samba drive finally show up.  It appears to be 
authenticating my connection.  After the waiting period, all is fast 
again.  On other hand if I walk away from my desk for awhile and Window 
Explorer is already on the samba drive, there is no hanging when I return 
and click on something on the samba drive.  In short, my workstation hangs 
when initially clicking on the samba drive from Windows Explorer.  Does 
anyone have any ideas?

I have also noticed that if I go to DOS and change directory (cd), it 
comes up quickly, and I can even edit a file on the samba drive from DOS 
with no problems.  If I bring up Windows Explorer immediately after 
editing the file in DOS, my workstation hangs again.

Below is a condensed version of my smb.conf.  I have also tried adding 
SO_KEEPALIVE IPTOS_LOWDELAY to the socket options.  That did not help 
either.

[global]
  server string = Samba server 
  log file = /var/log/samba/%m.log
  max log size = 50
  security = user
  socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
  dns proxy = no 

[opt]
  comment = opt directory
  browseable = yes
  path = /opt
  public = no
  valid users = myuserid
  writable = yes

Thanks in advance for any responses!