Lindsay Lohan and America Ferrera

Who was the real Mean Girl on the set when Lindsay Lohan resumed her Ugly Betty run — the tabloid mainstay, or series lead America Ferrera?

The New York Post's Page Six column claims that after some indecent behavior — including, perhaps, the forgoing of bloomers for a scene in which Betty yanks down her high-school nemesis' trou — Lohan was abruptly cut loose from her guest-star turn, which this season was to last six episodes.

A pal of Lohan's, however, argues to the paper that Ferrera "was mean to Lindsay" and "got her kicked off" the last two episodes she was supposed to film. A spokesperson for Ferrera would only tell the Post, "America is grateful to have had [Lindsay] on the show and thinks everyone should tune in to see how great the episodes are."

Other online accounts of the alleged on-set squabble claim that not only was Lohan's visit truncated, but that she is now being edited out of anything that already had been filmed.

Well-placed sources, however, tell TVGuide.com that such "editing" rumors are completely untrue, yet confirm that Lohan's run will end early — strictly for "storyline purposes." Summing up the rash of Thursday-morning gossip, one setsider tells us, "It's all so silly."

A statement from the show's producers reads: "[Lindsay] did a great job and we enjoyed having her. Viewers can look forward to her episodes tonight [at 8 pm/ET] and next week." Lohan's publicist, Leslie Sloane Zelnick, has yet to respond to our request for comment.