samba - May 2002 - Cannot connect to server upgraded from 2.0.6 to 2.2.4

I recently upgraded a samba server that had been running 2.0.6 to 2.2.4 
because I could not authenticate to it from windows XP clients. 
Unfortunately, I'm not able to connect to to the new installation. Windows 
reports that '\\[server] is not accessible' and 'The semaphore
timeout
period has expired'

The problem seems to be caused by lock contention on the secrets.tdb file. 
For whatever reason, any SMB server on campus ends up being probed alot. (I 
don't know if it's bored students or something that some windows
OS's just
do, but it happens.) This means that I'm not the only one trying to access 
my server.

In any event it seems as though some of the time, after acquiring a lock on 
offset 656 of secrets.tdb, an smbd will go and select() on it's network 
sockets. This means that if the client does not respond immediately, all 
the other smbd's will, within short order, block on that lock. It is not 
the case that all the smbd's block holding the lock, but some do.

Since I know people will ask, here's my smb.conf:

[global]
   encrypt passwords=yes
   update encrypted=yes
   workgroup = CAMPUS
   null passwords = no
   load printers = no
   wins server=wins.andrew.cmu.edu
   local master = no
   name resolve order = lmhosts wins host bcast

[wincd]
  path=/usr0/wincd
  writable=true

[tmp]
  path=/usr0/wintmp
  writable=true