You have to temporarily install a driver that includes a unschedule() statement. I did it by modifying an existing driver as I described above. When you install the modified driver hit configure and save, then uninstall it by replacing it with the generic Z-Wave repeater driver. At least that's my understanding, there may be a way around it that I'm not aware of.
As to how it happened I'm not sure but it probably resulted from switching drivers in my case.
