I am running the "LED_button_callback" example code using IAR. The project compiles and runs fine when I select "Download and Debug" under the "Project" menu. I am able to push buttons SW4 and SW5 and see the correct LEDs toggle. My problem is when I try running the code without the debugger. The two LEDs come on but pressing the buttons no longer toggles the LEDs. What do I need to do to get the firmware to run standalone without using debug mode?