Washington - Sales of new homes fell in March by the largest amount in more than a year, indicating that the U.S. housing market remains under strain despite some modest signs of improvement.The Commerce Department says sales dropped 7.1 percent in March to a seasonally adjusted annual rate of 328,000 units. That followed a 7.3 percent increase in sales in February. This figure was revised up from an estimate that February sales had fallen 1.6 percent. The weakness in March could reflect that a warmer-than-normal winter caused sales that normally occur at the start of the spring sales season in March to occur in February. The median home price was $234,500 in March, down 1 percent.