In order to speed things up, Monotone Browser caches file information whenever it is fetched from Monotone. This helps to speed up certain actions such as displaying the contents of a folder or searching through files. Consequently the first time such an action is performed it will take the normal amount of time, but thereafter it will be much faster if not instantaneous.
Each Monotone Browser window has its own cache to store information about the revision currently being viewed. If that revision changes or the user left licks on the Reload tool-bar button then the associated cache is emptied and any file information is re-fetched from Monotone.
There may be times when you want to reload the database (such as to have access to new branches that have been added as a result of doing an mtn sync) but you do not want to invalidate your cache as you know it will come in useful later on. One way you can do this is to launch a new Monotone Browser window by left clicking on the New tool-bar button, within this new window left click on the Reload tool-bar button and then dismiss the window once it has finished reloading. This way the new database gets reloaded into Monotone Browser without affecting the cache associated with the original Monotone Browser window.