It’s vital for UI elements to be consistent across different parts of an application, so as to improve learning curves, encourage familiarity, ease of use and recall of how to use. However, if a particular part of the application requires a different visual treatment or UI element or behavior due to the nature of the context (a form layout vs. a table or tree), then by all means just do what makes sense for that context–do the right thing! Forcing consistency for the sake of consistency isn’t the best prescription if it conflicts with the needs of a certain context/situation.