My assumption, which could obviously be very wrong, is that having the list with the row commented out causes no error. End result is what I want. However, setting the item to nil isn't the same as the item not having existed in the first place. So I sort of expect I could do what I want to do.
Most of the addon code is not mine... so your right, it's likely be a referencing something else. Perhaps rather than simply removing the array item it's nil'ing the widget control. One of the many challenge of trying to unravel addons from the olden days.
I'd kill for a solid debugger. Thanks