Here's a screenshot taken from the "test" Slackware Linux box.
The previous screenshot was taken from a FC14 Linux box that was connected over HTTP to the same Untangle server (192.168.2.254) via VPN tunnel (unfortunately, each time I need to take a screenshot using the "test" Slackware Linux box, I have to jump into the car and drive over to the site ... I thought I'd save some time ... and fuel).
As you can see, I'm able to connect over HTTP to the Untangle server admin page using the "test" Slackware Linux box. I'm running 4 other Untangle installs, but have never encountered this issue before. The reason that I (mistakenly) thought it was as a result of the Directory Connector was because the problem started after the trial expired.