Nothing happens when I hit partial filter / How do I deselect parts of the video

[Jabberwockxeno]

So, I am trying to deinterlace only part of my video.

I go to video filters, add a bob deinterlace, click it in the active filters side, hit partial....
And nothing happens.

Yeah.

So, what do I do?

Also, if I have selected a part of a video with the A/B buttons, how do I DE-SELECT the part?

EDIT: I'm using 1.6

[Jan Gruuthuse]

Move to start of video and select [A ], move to end of video and select [ B]?