nbd-server doesn't release connected clients

[Anthony Simonelli]

Hi everyone.  I'm running Ubuntu 7.10 and LTSP 5.0.39.
 This uses the nbd rather than nfs to serve the kernel
and all the other stuff to the thin clients.  What
I've noticed is that when I reboot the thin clients,
netstat reveals that it creates a new connection to
the nbd server every time.  I've rebooted the same
thin client three times so it displays the following:

tcp        0      0 192.168.0.10:2000      
192.168.0.146:48587     ESTABLISHED
tcp        0      0 192.168.0.10:2000      
192.168.0.146:34316     ESTABLISHED
tcp        0      0 192.168.0.10:2000      
192.168.0.146:54989     ESTABLISHED

Is this normal to keep these established connections
or a bug?  A reboot of the server certain clears that
up, but is there a better way?