Shares of motor home manufacturer Winnebago ( WGO) were falling in morning trading after the company said third-quarter earnings dropped by nearly half, due mainly to lower sales volumes. Results missed analysts' expectations. Shares of the company were down about 8% recently at $36.75. The company earned $9 million, or 48 cents a share, in the quarter ended May 31, compared with $17.7 million, or 88 cents a share, in last year's quarter. Analysts expected 67 cents a share. Revenue was also lower at $200.2 million, down from $245.9 million. "Due to the lower sales volume, we reduced production schedules to better align the company and dealer inventory levels with retail demand expectations, decreasing plant efficiencies," said Chief Executive Bruce Hertzke. The company said it ran on four-day workweeks at its factories for the first six weeks of the quarter. Motor homes shipments also slowed, the Forest City, Iowa, company said, citing dealers trimming inventory levels as a result of lower consumer confidence levels, uncertainty about the war in Iraq and the coming model year changeover.