Hi Roger,
Thanks for the sample. That makes sense since at that point (when the button enters the QAT), it's binding is still the same but the DataContext being inherited down has changed due to the visual ancestor change. Thus the binding doesn't resolve to a command.
I did some research and found that it was the updates in 2010.2 that caused the behavior change. Namely, ths item:
Improved the CloneService to clone bindings made on dependency properties.
Prior to that, bound items would get their resolved values cloned with them instead of retaining the bindings.
You probably want to attach to some of the CloneService events like CloneCreated and in that, update the binding. Alternatively you could set the DataSource of each clonable button, but that's probably not as attractive of an option.