Now if only I could figure out how to post youtube videos...fails every time I try.
There are three important rules to posting youtube vids so that the thumbnail displays.
1) Enclose the link for the video in the [youtube][/youtube] tags.
2) Remove the "s" from "https" to use the unsecured link.
3) Don't use urls from vids within a playlist. You have to use the direct link.
( "http://www.youtube.com/watch?v=qTx-sdR6Yzk" will display a thumbnail but "http://www.youtube.com/watch?v=qTx-sdR6Yzk&index=3&list=PLlMwJ0HGPsL--7jtTMC8MSsjljY6OZbAB" won't even though they point to the same video.)