Browser versions and OS (and desktop environment, if applicable)
Firefox 17.0.8 ESR, Win 7 64bit
After calling tree.disable(); it is greyed out. So far so good. But I can still click on it and change selection. Clicking right still brings the context menu of the tree up.
Seems weird to me. In comparison, grids are kind of dead, if disabled, as they should be.
Calling tree.disableEvents(); prevents selection as it should. But contect menu is still accessable.