The tube should have a bit of air to give it some shape before installing. That helps prevent the tube getting pinched in the bead of the tire during installation. Inflate to 40 psi, spin the wheel and make sure it seems seated equally all the way around. If the tire is "popping" or exploding suddenly, then you are doing it wrong by over inflating or pinching the tube under the tire bead. If the tire goes "pssssss" slowly flat, then it's a pin hole caused by a tire lever, or other sharp object.