Normally, when multiple applications are available to complete an action, Android ask to the user which application he wants to use.
But in this panel, you have a small checkbox to remember this choice.
To clear this association :
Go to Settings -> Applications, then select the appliation which is currently launched for the action. Scroll down and select ‘Clear Defaults.’ The next action you do that requires a default will ask you to select either the application to complete the action.
