chromatic, you are my hero!

I thought I was cleaning up all references. But your post made me look again, and I realized that the problem was that I'm using interrupts to end the program when it runs as a daemon, and I wasn't cleaning up $log in the interrupt function which performs an 'exit'. And this tells me why I wasn't getting the error when I first started using the class, because I was working with the build mode, which doesn't fork and needs no signal to be stopped.

Thanks so much for your guidance. Happily, I can now move onto the problem that lead me to add extensive logging to my program in the first place!