Could be (a)"buy on the rumor, sell on the news" syndrome; (b)the notion that the "big dog" on the block (no pun intended) should have beat by more; (c) that sales and margins are still weak in Europe and Australia, with only the commitment by management to keep working on it; (d) a cautious forecast, pointing to a better second half of 2012 than the first half; (e) poor government sales; or (f) all of the above.
Staples is still best of breed in this segment, but until the economy improves even best of breed will suffer. I picked up a few more shares at $15, but might have to be happy with the dividend for a few weeks/months.