Anyhow, there still seems to be a problem in the with-output-as-gadget setup. I end up in the debugger with some layout function calling sheet-native-transformation on the parent of the check-box-pane which is NIL at this time. Anyone got a clue as who is responsible for providing a parent for this thing?

The problem here is caused by the call to allocate-space in the initialize-instance :after on gadget-output-record. Not calling that results in no errors and a check-box gadget being displayed. I have no idea if this is an appropriate fix but hopefully this will provide food for thought for those that are in the know. Paul