drgnz23 My short answer was not much of a help.
I would most strongly recommend that you get an electrician in to look at this ASAP.
I am not familiar with zinco breakers, but dimming lights in combo with breakers that show signs of arcing is a situation that deserves proper attention.
Be prepared to do a panel change as the bus bars in the panel may (most likely) be damaged and will not be repairable.
