Similar is not the same...somewhere in the fixture is usually a sticker indicating what are the acceptable bulbs. Are you using one that is acceptable?
An IC rated box usually has a thermostat in it that will shut the thing down if it gets too hot. If they're defective, the opening and closing would be like you sitting flicking the switch on and off for an extended time - that can cause a bulb to fail quickly. Same thing about the switch on the wall, if there's a loose connection somewhere either at the switch or somewhere in the string supplying power. If they're all on the same breaker...could be the breaker, or the screw attaching the power leads to it or the neutral bar.
I'd look for a loose connection either at the switch or the supply if the bulbs you are using are on the accepted list.