Remote folder doesn't appear in finder window

Aloha all!

I am "the tech guy" for the Comm department at a small private university. This includes a 21 machine Mac lab, couple of classroom Macs, a streaming radio station (Mac, of course) and several faculty office Macs. As you may expect, I spend a lot of time shuffling data back and forth between computers, and I do most of it via Ethernet.

Now, the situation is a little odd in that most of the computers share a VLAN, while the faculty machines are on a different LAN. But we can talk between the networks easily enough, for the most part, by using IP addresses. Using the Finder, under the Go menu, selecting Connect to Server, and providing the IP address, then logging in remotely. Of course, remote login and file sharing are enabled on the target machine (actually, on all of them).

Usually this works as expected, and the target computer appears as a remote drive in the left-hand column of Finders windows under the Shared listing.

However, something different is happening with one of the machines. Connecting from the computer in the radio station to the computer used by our departmental secretary / radio station music director, her computer doesn't appear in the Finder. Or on the desktop. Or anywhere that I can find.

When we connect using the Go to Server function, a Finder window does open up displaying her user folder. But if we close that particular window, it is lost. Her machine does not show up in the listing of Shared computers, or as an icon on the desktop of the radio station computer. It does appear under the Go menu list of Recent Folders.

More troubling, since nowhere does it show up, once we have established the conenction, we can't terminate it.

Once we have logged in, if her folder gets shuffled off of the list of recent folders, we can't locate it anywhere. And we can't simply re-log in, because the computer still is logged in, and the option to connect is greyed out in the Connect to Server command.

Why isn't her computer appearing as a shared machine?

Mahalo,

Tom G