Yeah, draw the interface area so it covers the entire scene.
Check this tutorial
P.S: you only need to read the first bit really & the bit after the first set of images. Long story short. Interface image canvas size should be same size as your default game resolution. You then need to set the interface area so that it's the same size as your default game resolution or slightly larger. This should prevent any left or right clicks on the screen from triggering any new destination or action events.