When I built my wheels (XT hubs, A719 rim, 36 DB spokes), I used Damon Rinard's spokecalc spreadsheet number of 600.5 mm and double-checked it myself. The spoke lengths worked perfectly. But it would behoove you to check it yourself. The variance won't be more than a mm or two.
Just saying "incorrect" doesn't help the OP at all and is contrary to my own experience.