Network connections between XP and W98 machines don't always close readily

Occasionally, after accessing my Win98 machine through my XP one, when I try
to shut down the Win98 machine, it'll state that one user is still connected
and do I still wish to shut down? I'll click "yes," and it shuts down.

If I then re-boot the XP machine, I will see the "Closing Network
Connections" screen during the shutdown (it hung one time on this screen and
I ended up powering off/on to reboot).

Other times, however, this doesn't happen.

I'm curious if there's a ready explanation for this and if there is any way
to manually close the network connections in XP to prevent any possible
hanging at shutdown.

Both the Remote Access Connection Manager and the Remote Access Auto
Connection Manager services are set to "manual," if that's pertinent.

Bruce