ActionScript 3.0 :: Converting Gameloop To Miliseconds (from Seconds )?

I have a gameloop, where I used to calculate the timedifference in seconds for time based movement.

ActionScript Code:
var currentTime:int = getTimer();
var currentTimeDeltaInSeconds:Number = (currentTime - _lastTimeUpdated) / 1000;

now I've decided I want to use Miliseconds, so it looks like this:

ActionScript Code:
var currentTimeDeltaInMiliSeconds:Number = currentTime - _lastTimeUpdated

So I've converted speed variables, by dividing them with /1000, it looked like this before:

ActionScript Code:
var currentTimeDelta:Number = 0.036 ; // in seconds
var speed:Number = 50;

[code]...

- But the result is still not identical, position is still 1000x more, I know it has to do with multiplying the velocity with the timedelta, which is 1000 times greater with miliseconds, but I dont understand why is it like this?