I've noticed time of the day seems to make a huge difference on both playing videos and loading videos. My lache one didn't work for the entire day, I tried multiple times... then I chucked it up in the evening and it was no problem at all.
I was going through the same issue though, I really want D.Tube to be better, because I want to use to expand on my posts... the little lache video just doesn't make sense on my YouTube channel.... I've also noticed that sometimes @dtube will upvote a dtube video... and it's upvote is worth like $50... so that's pretty motivating...