I ordered these lamps in a pack of 4 and was happy with them for about a month. I ordered them on May 7th and it's now June 4th and I'm already changing the first one I installed. The bulb should work for more than 3-4 weeks. I'll update if another one comes out soon. Maybe I got 1 out of 100 defective ones. What percentage of defects do they have at the factory?