samba - Nov 2002 - How can I read and write a file at the same time?

My usage scenario is one Samba 2.2.5 installed on FreeBSD as server, and 2 
windows 2000 boxes as clients, both mapping to the same share as the same 
user to Samba server.  While one Windows box is writing a file, I start 
reading on the other Windows box.  It always fails even I have
"locking",
"oplocks" all as no in the config.

Does anybody know if there is a way to make this work, or the reasons that 
this should never work?

Thanks,
Chere