Bolstered by sales of the new iMac, Apple was one of just a handful of PC companies to post year-over-year gains in unit sales despite an overall decline in worldwide PC sales, as reported by c|net. Overall, unit sales were up 5.4 percent worldwide and 6.7 in the U.S. from the previous year, according to market researcher IDC. Apple climbed one spot to be the No. 9 computer maker in the world last quarter.