I've been testing most of the episodes, and it seems that only the first episodes of each season works.

lemon is right, only first episodes of each season work, all other fail and say 'cannot play this video'

I've contacted the developers and they have put up an entirely new app on the market. It appears to work (comments), but I'm not sure if it'll work for long.
They claimed "hackers" got into their servers to steal the videos -.-" ... Not sure if this is just an excuse.
But anyway, there's a working version on the market, I've been unable to find a free apk for it though.

found a working version of this app.
http://www.duckload.com/download/Yseb2