A new report from IDC says that PC sales are off about 3 percent in the last quarter. The research company cites the continued growth of tablets (well, the iPad anyway) and the quake in Japan as possible causes. People have been a little too occupied in Japan in recent weeks to worry about buying new PCs. Unrest in the Middle East may be a contributing factor as well. Nonetheless, the company expected a small rise in PC sales as the economy picked up steam but instead the numbers fell. Gartner, another firm, said PC sales were down 1.1% world wide but down over 6% in the United States. Circle April 20th, by the way. That’s when Apple reports on iPad sales.