I have the same bulb, using a clamp light fixture... My first bulb burnt out in about 3 months, the second one only lasted a month....defective for sure... But I finally struck gold. I got one that works fine, have had it for 5 months now, and have another one sitting for when I need to change. Another site you can try that I have bought other supplies for super cheap is
www.herpsupplies.com Their shipping cost is great, and their products are cheap. The bulb is $13 on that site.... I bought a tonne of stuff (over 10lbs worth of product) and had it shipped to canada for only $30 Priority shipping. They have a shipping calculator on the site. Stuff ships the next day! Check it out... They also have different types of bulbs, so you can try another brand. GOOD LUCK!