Counter not stopping

[behem0t]

When I'm starting timer with a button(switch) and changing refresch intervals during counter run, when countdown it's at 0sec its starts again. When I'm not changing refresh intervals or starting counter at loop start its working fine.

So I can run it by button but then I can't modify refresh intervals during countdown.
Or I can modify intervals during countdown but it must be started immediately at first loop (with arduino boot)

I think something with Mills() doesyn't fit :) and end action is not triggered.