My Driver's Side HID light Flickers then goes out.?

I installed a set of dual beam HID headlights in my 2005 Nissan Frontier 2 Months ago and now the driver's side HID light flickers for 5 second then shuts off, the passenger side stays on. I'm thinking it's the bulb and not ballist since I am getting power to it? If so does it matter if I buy a different brand bulb? What brand? Where's a good site to buy from? Does it matter which bulb since I have the dual beam set up? Thanks Guys.