I can't even see that any movie is added in the media tab on k2. as soon as i browse to the tab it just downloads the movie. the same happens if you browse to the page where the media is supposed to be displayed, it just downloads the video.

I have never seen this happen before and wondering what is happening.

Mov files are only supported in certain browsers (Safari), other browsers cannot stream them.
I would suggest using a different video format like mp4.