Firefox constantly freezes since Norton 360 update in October

Hi -- Ever since the latest Norton 360 update (in October), my Firefox constantly freezes about every 30 seconds.  It will freeze for a couple seconds, then work again. But it does it constantly.  I've tried rebooting, but that doesn't work.  I located an old post from 2012 stating the same problem, and that it seemed to be associated with the Firefox/Norton toolbar.  Disabling the toolbar seemed to straighten the problem out, however, I don't really want to disable the toolbar.  Can anyone offer another suggestion or solution?  Thanks!