I've tried Replay Media Catcher and it doesn't have any problem downloading live rtmp:// .flv CNN video. I haven't tried to use the grid octoshape plug-in. I try to stay away from unknown software to avoid malware and conflicts with other software. The less software you install, the better your OS works.

Please note that live streams are more difficult to download/rip, so you may prefer to use screen video capture software instead.