The Timeline dialog box contains two options for Timeline editing. Click on the Options button to open the Timeline Options dialog.
Tick the Animate Popup option if you want the popup box for the added action to slide open. If the option is unticked, the popup box will simply appear below the action. By default this option is ticked.
Tick the Auto Edit option if you want the popup box for the added action to appear when you add an action. With this option unticked, you can add a number of actions before you begin to edit their settings. By default this option is ticked.
Tick the Single click insertion mark option if you want the insertion marker to move to any location with a single left click (outside any actions). With this option unticked, you can only move the insertion marker by dragging it. By default this option is ticked.
Click outside the Timeline Options dialog to close it.