Shares of Wyeth ( WYE) fell Tuesday as the drugmaker's fourth-quarter earnings came in below Wall Street estimates. Also, the company's guidance for 2007 was at the low end of analysts' expectations. By early afternoon, Wyeth's stock was down $1.03, or 2%, to $49.57, on heavier-than-average trading. Excluding special items, Wyeth earned 66 cents a share for the three months ended Dec. 31, 5 cents lower than the average estimate of analysts polled by Thomson First Call. Sales of $5.22 billion beat the Wall Street estimate of $5.1 billion and the year-ago quarter's $4.75 billion. When items are included, Wyeth earned $855.4 million, or 63 cents a share, vs. a profit of $731.7 million, or 54 cents a share, for the year-ago quarter. Wyeth set its 2007 guidance at a range of $3.40 to $3.50, excluding items. The Wall Street consensus was $3.49. Analysts participating in Wyeth's conference call Tuesday focused on a plant in Puerto Rico, which has been the source of continuing discussions with the Food and Drug Administration over manufacturing problems. Until the matter is settled, Wyeth can't make new drugs there, including several which it had hoped to launch this year. Bernard Poussot, Wyeth's president and chief operating officer, revealed Tuesday that the FDA began reinspecting the plant last week. He added that it would take the agency several weeks to complete its review. Fixing the problems to FDA satisfaction "has been a majority priority over the last seven months," Poussot said.