well i don't know how this one ended, but now i'm in the same boat.
my HID headlight started going off intermittently several weeks ago, mostly when i would be still at a traffic light. so i didn't think it could have been anything loose. then it seemed fine for a few weeks before it started doing it again and then i lost my light completely. i just figured the bulb was spent since it was about 2 years old and my last one went out at about the 2 year mark. so i'm a little perturbed that these bulbs are only lasting 2 years, but still a helluva lot better than halogen.
so i replace the light and it doesn't work. i check connections/fuses and reconnect everything and then it works. i scratch my head, but whatever. it works for less than 2 days and now my new light is out. it actually went out while i was in a drive-through. i shut my bike off because of long wait time, turned it back on, and then the light was gone. good thing i wasn't too far from home. but nothing i could do could get my light back, so i figured it must be the ballast. it's about 4 years old and they don't last forever either, especially the higher 55w ones which i have. so i order a new ballast and it comes in yesterday. i hook it up to the new light i installed last week and still no light.
when i checked the fuses before, the 25amp fuse in my HID relay kit looked horrible, like it had slowly been melting over the years. but the fuse still looked intact so i left it alone before. well now i replaced it. still nothing. so now i'm guessing i blew my new light before somehow. so i have another new light i hook up. still nothing. so now i'm really confused and ticked, and i retrieve my old ballast out of the trash because i have a hunch. i hook up the old ballast with the new NEW light, and now it's working. HOORAY!! so i figure the new ballast must be no good, and the old fuse must have gone bad. but i still can't explain why my previous light would stop working for a few moments and then come back on. bad connection on the old fuse? i don't know. for all i know, this still isn't over and my new NEW light will stop working as well. i'll be back here if that happens....