samba - Jan 2007 - samba is freezen when is accessed by two different computers at same time

Hi all, 
 
I just installed Samba 2.2.12 on a HPUX 11.0 (192.1.1.1) and I'm sharing
nfs "samba" data on another cpu (192.1.1.8).
 
bdf (192.1.1.1):
192.1.1.8:/dsp1/fontes 14540800 13990536  517304   96% /nfs/fontes
 
>From a windows xp (professional) computer I can do copy, paste, etc . If
I call a cobol application, it run ok too, but when another user calls
the same cobol application from another computer then the first one,
both of them become  frozen. After that, the process must be canceled
and if you retry it, nobody can run it again.
The samba web administration tool shows Active Connections, Active
Shares and Open Files, like below, but no kill action clean the status.
A cpu must be restarted to clean these conditions.
Active Connections
PID Client IP address Date Kill 
5294 dsp000-111 172.16.0.159 Wed Jan  3 11:03:51 2007   
5348 dsp000-149 172.16.0.198 Wed Jan  3 11:06:34 2007   
5331 dsp000-149 172.16.0.198 Wed Jan  3 11:05:27 2007   
4483 dsp000-001 172.16.0.14 Wed Jan  3 10:34:32 2007   
 
Active Shares
Share User Group PID Client Date 
fontes fontes users 5294 dsp000-111 Wed Jan  3 11:03:56 2007  
fontes fontes users 5348 dsp000-149 Wed Jan  3 11:06:34 2007  
fontes fontes users 5331 dsp000-149 Wed Jan  3 11:05:27 2007  
IPC$ smbnull smbnull 5331 dsp000-149 Wed Jan  3 11:05:27 2007  
fontes root sys 4483 dsp000-001 Wed Jan  3 10:34:42 2007  
 
Open Files
PID Sharing R/W Oplock File Date 
5294 DENY_NONE RDWR  EXCLUSIVE+BATCH  /nfs/fontes/SPA010 Wed Jan  3
11:04:32 2007  
5294 DENY_NONE RDWR  EXCLUSIVE+BATCH  /nfs/fontes/SPA025.idx Wed Jan  3
11:04:32 2007  
 
This condition doesn't happen when the same application is running on a
unix environment. You can do it from several computers and they run
without errors.
 
Thanks a lot for any tip.
 
Gerson