FUNNY HA-HA, OR FUNNY STRANGE? Comedienne Wanda Sykes stunned the crowd at the Michael J. Fox Foundation for Parkinson's Research benefit the other night when she joked about her uncle's battle with the disease. "She was onstage talking about duct-taping her uncle to a chair and she started imitating him, shaking a lot," a witness at the Waldorf-Astoria told Lowdown. "Everyone kind of hesitated and looked around before they laughed." Sykes' PR rep insisted: "She did tell an offbeat joke about him, but she didn't imitate him or act it out." The spy claims that Fox himself was laughing, but the actor's rep claimed ignorance.