replaced HID bulbs twice and still have porblems

I was so proud of myself I replaced the 1st bulb on my 2006 Prius 30 mins, but not so happy when it started to intermittently go on and off again. I bought the bulbs on ebay from a recommendation I think from this forum for 2 for $40. So feeling perhaps the 1st bulb was defective I replaced I replaced the second one in 15 mins. But after a few days of ok, once again it went out intermittently again. So could it be a bad ballast? Is it possible that both bulbs were defective? I'm willing to try again if someone could post a link to the bulbs that worked for them.

BTW this is an awesome link to changing the bulbs, I didn't even need to disconnect the power cord from the boot...

in not allowed to post the link (5 times thing) but it's on You tube called "how to change your Prius HID bulb in 10 minutes (part 1)" there's a part 2 as well. All I needed was a multi screwdriver

 

I did wear gloves, but I was also careful to never touch the glass. Can someone send me a link to a legitimate bulb retailer that they have used. Thanks

 

Is it possible it "the control module" and not the bulbs. I read this on a parts website? Can anyone tell me what the control module is? and can I replace it?