SQL Server 2008 started reporting the statement duration in microseconds in scripted traces. That’s one millionth of a second. Previously they were reported in milliseconds. Profiler automatically corrects for this and always displays in milliseconds regardless of the version of SQL Server that generated the trace. However SMO reported them in milliseconds or microseconds depending on what version of SQL Server generated the trace. Worse, SMO has no way to tell you what version of SQL Server generated a trace. Or what unit of measure was used to return the value.
This is a companion discussion topic for the original entry at http://billg.sqlteam.com/2011/07/03/tracetune-display-duration-in-milliseconds-finally/