Season four started four months after the end of season 3. Johnny Galecki submitted the episode "The Benefactor Factor" for consideration due to his nomination for the Primetime Emmy Award for Outstanding Lead Actor in a Comedy Series at the 63rd Primetime Emmy Awards.
He confesses that Bernadette caught him engaging in cybersex with a fellow World of Warcraft player, who is later revealed to be one of Howard's male colleagues at Caltech.
Howard and Bernadette later meet at the Cheesecake Factory and after Howard reveals the reason he indulged in cybersex (he thought that Bernadette was not interested in having sex with him), they make amends and decide to give their relationship another try.
Leonard fails miserably when he attempts to play the game.
However, Amy's presence does not go down well with the other guys, who already find it difficult to handle Sheldon himself, and they start hanging out at Penny's apartment to escape "Sh Amy" (the name the guys and Penny gave for the couple).
Due to the diet of cruciferous vegetables he has a bad case of flatulence and he tumbles down the stairs while going down for his jog, Sheldon builds a robotic replication of himself which he calls a "Mobile Virtual Presence Device" (the telepresence robot by Willow Garage) that would go through all the hazards of life that Sheldon would otherwise have to endure, while he stays behind in a "secure, undisclosed location" (his bedroom).
The guys dismiss the MVPD as a stunt (Penny calls it Shel-Bot).
When she returned to the series, she was shown working as a bartender instead of waitressing at her usual workplace, The Cheesecake Factory, to hide her injury.
In January 2011, The Big Bang Theory was renewed for an additional three years; extending it through the 2013/14 season, for a fifth, sixth, and seventh season.
Though Howard hides under the table when he sees Bernadette, the incident nonetheless reignites his feelings for her.