Take a look at your OEM headlamp, seeing how they made a ventillation hole + ruber tube so that the vacumm will be sealed without condensation yet the oxygen will not burn all out? The same thing for your corners as well. Simple physics: Oxygen helps keep the "flame" going, so, without any oxygen, your bulb will be forced to light up, yet will shorten its life.

So try to see how they construct the thing and hopefully it'll help you out.

Other reason is that the overload input voltage and current (or their products known as Wattage) will burn out the bulbs. Check to see if the bulbs' wattage input is NOT LOWER than specified input wattage for your headlamp.

Sorry for my babling.......