Hard-partying supermodel Kate Moss was wildly wobbly at the Yves Saint Laurent runway show after-party in Paris this week and had to be helped up several times. Witnesses said Moss showed up late for the YSL bash at Le Trianon on Monday. She appeared unsteady as she sauntered up to the front of the room near the stage, where a rock band performed. “She danced so hard that she had to be helped up several times by security,” said a witness. “She went a little crazy.” Paris fashion week insiders were still snickering about Moss’s boozy behavior days later, after she walked the runway in the Louis Vuitton show smoking a cigarette. Calls and e-mails to Moss’ reps in the UK went unreturned, and a YSL rep didn’t return e-mails. Moss spent a month in rehab in 2005 after photos were published of her snorting cocaine. She checked into the Meadows Clinic in Phoenix, Ariz., where her stint must have gone well — she reportedly recommended that her pal John Galliano go there after Dior fired him over his anti-Semitic slurs in a Paris café.