This is a pain in VS 2010, here's my workaround solution.
public string DurationString
{
get
{
if (this.Duration.TotalHours < 24)
return new DateTime(this.Duration.Ticks).ToString("HH:mm");
else //If duration is more than 24 hours
{
double totalminutes = this.Duration.TotalMinutes;
double hours = totalminutes / 60;
double minutes = this.Duration.TotalMinutes - (Math.Floor(hours) * 60);
string result = string.Format("{0}:{1}", Math.Floor(hours).ToString("00"), Math.Floor(minutes).ToString("00"));
return result;
}
}
}