Multires smoothing border does not work.

Hi! i have problem with blender smoothing brush problem.
When i am normal mode smoothing out border is all okay
but if i enable Multires, smoothing out the border does not work :c

I though high vertices causing this issue, so i down setting to low poly and check again.
still border is being locked and i can’t working with model.

Is there is way to fix border being locked?
This happen only with smoothing brush sadly.

I am using 2.73a right now.