MPG and softlimits

[vdl]

Setup:
* I have set softlimits for all axis.
* I'm using mpg to move axis

Problem - when movement "step" is more than softlimit remaining it does not go till softlimit and stops there, but stops in some random distance before reaching softlimit. After 2-4 tries it goes to 0 and stays there.
Example:
MPG step is 0.4
Z position is 0.32
Z softlimit - is 0

Operation: Moving to -Z one step
Expected: Moving to Z 0 and warning about soft limit ( is it possible to disable that warning? )
Reality: Z stops at 0.1250 and shows warning,
I dismiss warning, step again
Now Z stops at 0.0175
3rd attemp stops Z at 0

Another try from 0.32
stops at 0.07
then at 0

When using keyboard movement then softlimit is reached without problems