Mozilla - Firefox - Bon Echo crashes

One thing that has been happening very regularly on my Intel iMac is that all non-Safari browsers that I use have been locking up. This happens frequently with no consistent pattern involved. Bon Echo -- an Intel compiled build of Firefox which is normally very fast, is the biggest culprit, but it also happens with Firefox and even Mozilla. It may be time to check the plugins since I've reinstalled the latest versions and they still crash.