Friends has been affected by the US terrorist attacks.
The third episode of the new series has been re-shot because it was due to take place in an airport.
The episode was supposed to feature Monica and Chandler arriving at the airport several hours before taking off on their honeymoon.
Friends executive producer David Crane said: "A lot of it had to do with how ridiculous it was for crazy, obsessive Monica to want to get there three hours in advance.
"Two weeks ago, that would have been ridiculous. It's not ridiculous now. Everybody's doing it now. A lot of the comedy in it didn't feel funny, so we re-shot the story line."