hi, last month i decided to change the xenon bulbs on my 172 sport. after i put them in the drivers side decided not to work for some reason and when u hit the unit it would flicker and go off again. i assumed it was the ballast pack causing this so today me and a mate put the new ballast on and it worked for a couple of seconds then went off,when i took the bulb out it had broke in half!! could this problem be the ignitor?? iv'e just ordered another 1 off renparts. both ballasts work fine and the other ignitor works fine. any advice would be a help as its turning into an expensive pi** about! thanks