okay oldest son just came in and said that the .flv files are hard to play on just about anything! He suggested using vixy.net. You enter the link that you wish to download, choose the format that you want to use (ie; mp4's, mp3's, avi's, mov's and 3gp's).
He said to make sure that the video page that you are wanting to download is closed while you have it in vixy. He said that it recognizes that it's open and it will take twice as long to download. Hope that makes sense. If not, again, just give a shout out and either of us can walk you through. Looks simple and straightforward without having to download or install anything.