All of the buttons, including the arrows and mode buttons on the Launchpad are assignable. When assigned in Live's midi learn mode, this disables their original function on the Launchpad. If you find that any of the buttons stop working, you need to go into midi learn mode within Live to check that they have not been assigned to any of Live's parameters.
The image below shows the CC numbers belonging to the top row of "arrow" and "mode" buttons on the Launchpad and how they will appear if they have been assigned to anything in Live. The arrows send out CC 104 - CC 107 and the mode buttons (session, user 1/2, mixer) send out CC 108 - CC 111.
Before assigning any of the buttons, make sure that you are already in the Launchpad mode you wish to be in before going into Live's midi learn mode.