BullSticks

[puppman]

Very simple. The shorts are banking on this. People will sell starting tom through the delivery date and according to the SEC rules...
If you sell your stock before the ex-dividend date, you also are selling away your right to the stock dividend. Your sale includes an obligation to deliver any shares acquired as a result of the dividend to the buyer of your shares, since the seller will receive an I.O.U. or "due bill" from his or her broker for the additional shares. Thus, it is important to remember that the day you can sell your shares without being obligated to deliver the additional shares is not the first business day after the record date, but usually is the first business day after the stock dividend is paid"

So in essence they hope people sell and the price drops therefore being able to cover their shorts in addition to cover the divi.

http://www.sec.gov/answers/dividen.htm