Orders to U.S. factories fell 3.8 percent in January to their lowest level in 14 months, fresh evidence that manufacturers continue to struggle during the economic slowdown.</br></br>But another report showed that growth in Americans' productivity - - or output per hour of labor -- while slower, was still solid in the fourth quarter despite the sharp economic slowdown.</br></br>The Commerce Department reported yesterday that the January decline in factory orders, which followed a 0.6 percent increase in December, was led by a sharp drop in demand for airplanes, cars and other transportation equipment. Excluding the volatile transportation category, orders fell 0.3 percent, the third decrease in the last four months.</br></br>Factory orders rose 5.3 percent, the largest increase in a year, in the category of industrial machinery orders, which include those for computers. That followed a 3.2 percent decline in December.</br></br>January's overall performance was slightly weaker than the 3.5 percent decrease many analysts were expecting. The decline pulled orders to a seasonally adjusted $366.5 billion, the lowest level since November 1999.