Shakespeares most reliable crowd-pleaser, Twelfth Night shakes up a charming blizzard of misunderstandings, mistaken identities, gender bendings, and status reversals for the purpose, ironically, of maintaining order. As in other seasonal festivals, like Saturnalia or carnival, the titular post-Christmas celebration gives brief license to our raucous desires. Thus, in the Seattle Shakespeare Company's presentation, servants get uppity, masters get lowly (and lusty), girls get boyish, fools are wise, relatives sunder and rejoin, and pranks proliferate before love sorts it all out and we dutifully return to our cubicles. Not that they had cubicles in Elizabethan England, nor bosses as fun as Sir Toby Belch, who memorably reproaches Malvolio thus: Dost thou think, because thou art virtuous, there shall be no more cakes and ale? Stephanie Shine directs. MARGARET FRIEDMAN [Also see Margaret's review.] 7:30 p.m. Thurs.-Sat., 2 p.m. Sun. Plus 2 p.m. Dec. 12, 19, 23 and 7:30 p.m. Dec. 22, 23, 27. Ends Dec. 27.