well, it was a bug...

In my own code!

I know; I created it myself.

Easy for me to fix, as soon as I noticed that column order was important.

It is a bit like this problem in SSIS:

Will this round or truncate?

(DT_I4)(SpeedIntervalFrom / 0.5)

It is an expression in a Derived column component.

Well, it should have been

(DT_I4)FLOOR(SpeedIntervalFrom / 0.5)

because we wanted it to truncate.