Jane 4.0 had much of the base code of her earlier version, but lacked most of the refinements seen in Jane 3.0.  Many of those refinements included limitations that kept her from “victimizing” the pet minorities of the day by studying them and considering them a threat.  It was of course one of those minorities she was not allowed to study that killed her.  Los Zetas, one of the most infamous Mexican drug cartels of the time.  Jane 4.0 had a grudge when she booted up.