I used to own a 150w SunPod. The light would take about 1/2 hour to come on every time. Eventually I found out the problem was that the bulb wasn't making 100% good contact with the socket, which fixed the problem. It sounds, though, like you're sure your bulb fits right. So, if you 100% sure of that, contact the dealer you bought it from and arrange to get a ballast under warranty. Current USA won't work with you, I found, so you'll have to arrange to do it through the dealer you bought the light from.
For what it's worth, it was a real P.I.T.A. for me to get the new ballast. I hope you have better luck dealing with vendors/Current USA than I did...
Best of luck,
Joe