the problem with FPE Stab-Lok panels is a bit more extensive than was mentioned in the response. They not only become loose at the buss bar attachment but often require 150% of rated load in order to trip. So a 20 amp breaker may need 30 amps to make it trip. Some of the breakers have, under laboratory conditions, failed to trip under loads that went to 300% or more above their rated capacity. The worst offenders were the FPE Stab-Lok mini-breakers and esp. the double pole minis. Dr. Jesse Aronstein of New York has done a lot of research on them. You can direct clients, realtors, or anyone else to http://www.inspect-ny.com/fpe/fpepanel.htm for more information and test data.
