[Samba] Large file freezes, OpenBSD + WinXP x64

[Chris Zakelj]

I've been struggling with this for a while, and though it worked for 
about five minutes Sunday night, it's been a no-go ever since I built my 
server last summer.  What I've got:
Samba   (samba): OpenBSD 4.2-STABLE, samba-3.0.25b (from packages)
Laptop (osiris): WinXP SP2
Desktop  (isis): WinXP x64 SP2

I can copy/move anything and everything between samba and laptop.  I can 
copy/move anything between laptop and desktop.  I can *usually* copy 
small (less than 100M or so) between samba and desktop, and large files 
FROM samba TO desktop as well.  However, when I try to copy large files 
FROM desktop TO samba, desktop freezes.  There are no log messages being 
generated on the oBSD side (simultaneous tails on /var/log/daemon, 
messages, smbd.isis, smbd.smbd, and smbd.nmbd all remain silent).  The 
Windows event viewer likewise does not contain any obvious errors upon 
reboot.  Also of note, if I use laptop to move directly between desktop 
and samba, it always works (though more slowly, since it's only 100Mbit 
instead of 1Gbit ethernet, and is essentially performing every operation 
twice).

/etc/samba/smb.conf
[global]
   workgroup = ASGARD
   server string = Samba
   security = share
   hosts allow = 192.168.1. 127.
   load printers = no
   log file = /var/log/smbd.%m
   max log size = 50
   dns proxy = no
#============================ Share Definitions 
==============================
[homes]
   comment = Home Directories
   browseable = no
   writable = yes

[printers]
   comment = All Printers
   path = /var/spool/samba
   browseable = no
   guest ok = no
   writable = no
   printable = yes

[storage]
   path = /samba
   public = yes
   only guest = yes
   writable = yes
   printable = no
   case sensitive = no
   oplocks = no
   create mode = 0777
   use client driver = yes

Any ideas and/or suggestions on where to look for my problem, or what 
knob I may have improperly turned (or need to turn) to get things 
running well?