Seems like a couple recently-submitted YT videos have had problems with their thumbnails.

http://www.videosift.com/video/Guru-Josh-project-infinity-2008
http://www.videosift.com/video/Un-ing-believable-Japanese-Slide-Trick
http://www.videosift.com/video/Tales-Of-Mere-Existence-I-Can-t-Sleep

All three of these are YT videos, so everything should've been fine. Instead, for me, after clicking the final "Submit" button, the page with the video with 0 votes never loaded and after some 5min of waiting I got a System Error. Pretty sure it's the same case with Enoch's video.