The issue I am experiencing is similar to, if not the same as, what is described in this thread.
I am using Unity 5.3.3f1 Personal on Windows 8.1.
I have two UI Image controls used to trigger movement and a third UI image control used to trigger jumping in a 2D platformer. All Image controls have an Event Trigger component attached, in which all controls are firing the Pointer Down event.
\The jump button works if I press it by itself. However, it does not work if I am holding one of the movement buttons down. Do I need to do something else?