For 90-year-old Walter Cronkite, traveling can be a serious pain. Forgetting the lay of his new room one night recently, he ran into a table and broke two ribs. His girlfriend, Joanna Simon, says he rose to answer the phone without turning on the lights in his room in England, where he was working on the documentary Legacy of War, and he spent two days in the hospital under doctors' observation. “He’s absolutely fine, but in such pain he can’t eat, he can’t stand up, he can’t sit down, and he’s miserable,” Simon told us at a dinner screening of In the Shadow of the Moon, a documentary about the surviving moonwalkers, the former CBS anchorman was scheduled to host last night at the Plaza Athenee. Legacy production has been put on hold for four to six weeks — Cronkite’s expected recovery time. “He wanted to come tonight, but he couldn’t stand up in order to walk into the room.” Simon's nursing duty mostly consists of giving Cronkite Tylenol now that he’s off codeine. “The codeine really knocked him out,” she explained. And that's the way it was. —Amy Odell