I'm having the same flickering or dancing problem with my bulb jars too. It's driving me nuts, but after reading this thread as long as there isn't any soot or smoke i'm not going to change them. I use 4627 also. Which wicks are you using? I have tried CD, HTP, and LX. Now i am testing with zincs but it seems like i keep smelling a strange odor possibly from the metal core of the wick. Is that even possible or am i just sleep deprived? *faint*