The API methods should not change the initialization options. That means
1) If the widget was initialized with an enabled state 
2) Then the .enable(false) is called, 
3) Calling the .setOptions() should not result in reinitializing the widget in a disabled state(unless the "enabled" property is included in the arguments).

The same goes for the other scenario - initializing a widget from a disabled DOM element. That would make "disabled" the initial state, hence calling .enable(true) and then .setOptions() should result in a reinitialized widget with a "disabled" state.

The fix addresses the second scenario.

If you want to persist the disabled state after calling .setOptions(), you should include the enabled property in the arguments.

Regards,
Peter Milchev
Progress Telerik