Split audio from video doesn’t split video at the same point ?

Hi all !

When I move the cursor to a point over my timeline I'm not able to split both (audio and video) in at same time, at same point, with just one click. I have to choose between Video Tools -> Split or Narration Tools -> Split first and than other one, but frequently I face a problem, the audio disappears from that point forward.

I've tried unsuccessfully to click on video and later on audio, and vice versa, pressing Shift or Ctrl, to select both and then split together.

Answering likely questions:

    - Windows 7

    - Movie Maker 2012 (Live Essentials - build 16.4.3528.0331) - latest version 

    - I don't have problem with codecs or something else (I can watch and listen properly on preview before start editing)

I just wanna a single button or shortcut to split audio and video together.

Could someone help me?

Thanks in advanced !