Fans of Pasadena may have noticed that Alison Lohman doesn't always have the best hair days. It's not her fault. The actress _ who in real life has stylish, cropped hair _ wears a wig for the role. "I know her hair is in the process of growing out, but it was really short when they began filming," says a Fox spokesman for the series. Lohman, who also wore a wig for her role in last season's short-lived NBC series Tucker, had shaved her head for the role of a cancer patient in the 2002 Kevin Costner thriller Dragon Fly, according to her publicist. Then, she got the lead role in White Oleander, opposite Michelle Pfeiffer, in which she wears a different wig in practically every scene. But last July, Lohman gave a different version of the story. "I showed up one day with short hair and Mike (White, Pasadena's creator) was shocked," she said while first presenting the show to reporters. She also said that her shorter do would be incorporated in the show. NBC's Crossing Jordan is getting some support. The investigative drama starring Jill Hennessy is adding two supporting cast members, Kathryn Hahn and Steve Valentine (Nikki). Hahn will play Lily Lebowski, an "intake" liaison and office coordinator at the Boston-based coroner department, while Valentine plays Nigel Townsend, an ex-British soldier who currently works as a criminal investigator and forensics expert. Crossing Jordan, which has been renewed for the rest of the season, airs Monday nights at 10 p.m. _ Times wires