samba - Nov 2004 - Samba 3.0.7-2 keeps IPC$ pids after client shutdown or reboot

Hallo! 
 
I think (?!) I have a problem with that... 
I use Samba 3.0.7-2 on a HD-Install of Knoppix 3.7 (basically Debian Sarge).  
The clients are XP Prof. SP2. 
 
After I shutdown the clients, samba keeps the IPC$-pids showing in smbstatus.  
If I reboot the client I see in smbstatus the old and new PIDs of the 
IPC$-services. 
 
That is the last issue that keeps me back in giving our samba server free to 
use... 
 
Could You help me please to resolve this problem? 
 
Thank You in advance! 
 
Regards