While doing it, I had reason to use the application where I noticed the problem. Of course, I had to get everything going, because my machine went down for the usual Tuesday updates. And I went through the process and clicked OK before I realized that I was doing this in Chrome not Firefox.
And it worked.
For hackers, it is frustrating to have something fail to work when you don't understand why, but it is also frustrating for something to begin to work when you don't understand why. Chrome is on the update fast-track. Did they find my blog post and fix it overnight? Was my machine well overdue for a reboot, leaving my code encrusted in bit rot that needed a complete restart to clear out? Was it sunspots? Was it a hex? Was I just doing something stupid before? If so, what? I have no way to know why the problem is fixed, so I have no way of knowing when and if it will come back.
The fact that my code suddenly worked will probably be keeping my up nights for a while.
Granted, it is better for things to suddenly work for unknown reasons than for things to suddenly not work for unknown reasons, but both are a problem.