I did a job for a lawyers office recently where we retrofitted t-12 lamps and ballasts to t-8's. Rebuilt every light in the building. Upon completion when we turned the switches on we noticed a snaking spiral effect in the bulbs. Tried everything to get rid of the snaking in the bulbs! Finally I called the Sylvania rep and asked for his opinion. He said go to the switch and turn it off and on repeatedly 30 to 40 times. Did this and the lights burned perfect. He said you have to cycle the lights by doing this. The gases settle in the bulbs and the cycling clears it right up!!