SOLVED IT!
Note to self– don't let other people login to my pfSense box!!!
This install is in a fraternity house, and following the instructions from XBox support, one idiot unplugged my pfSense box. After I finished yelling at him for being such an idiot for an hour or so, I logged on and checked things out. Oddly, I noticed the ping had stopped. I ask the other 2 guys who have login rights about it, and I figured it out.
One of them entered "ping" under the "Command" option in diagnostics instead of using the Ping function. Since the command didn't return any data on that screen, he simply closed his browser and logged on again. Ergo, the ping command kept running in the background, doing exactly what it was told to do.
Additional note to self -- next time, login via a shell and run top before running to the forums.
Thanks for your feedback.
-E.Drav-