OK, So I have noticed lately, I'm discarding quite a few posts because I'm not getting any votes on them.
As it turns out, No one can vote if they can't watch the video.

The videos work just fine on LiveLeak but won't play in video sift.
Having a look on LiveLeak's site, I noticed a link at the top of each video that reads "Change Flash Player (If you experience problems)"
It looks like they have updated their video player. Clicking the link allows you to switch to V.4 instead of using the new V.5

They have obviously been experiencing problems with the player or they wouldn't have the link.
Clicking the link does nothing for fixing the Videosift posts but, I'm guessing, it's the reasons their videos aren't working here lately.

A few of my current posts that don't seem to be working on the sift but are working on Liveleak are:

http://www.videosift.com/video/Agreement
http://www.videosift.com/video/Tom-Brokaw-Explains-Canada-To-Americans
http://www.videosift.com/video/Obama-is-a-Liar-This-guy-Hates-Obama

This LiveLeak video works but seems to be using the old player:
http://www.videosift.com/video/Big-Business-Steals-Land