Malcolm in the Middle mom Jane Kaczmarek, who has been a no-show around the Fox comedy's L.A. set since early February, returned to work Thursday. The 46-year-old actress, who plays manic Lois, had been suffering from intense migraine headaches. Sources, however, tell TV Guide Online that her reps had been negotiating with the show's producers for a big pay raise. Her publicist denies any connection between her health and salary talks, but similar rumors about a "sick out" circulated in September during another of Kaczmarek's absences. (Her husband, actor Bradley Whitford, was among four members of The West Wing cast that threatened to walk out last summer over a pay dispute.) Kaczmarek's MIA status forced producers to eliminate two episodes there will be only 22 Malcolms this season, instead of 24.