For like the tenth time I just stumbled accross one character I that goes in on one side and out the other.
Would it be cool to have a sort of "force me" button that gives that character a special treatment (exact parameters could be set indidually)? For instance first having that character coming every two characters, for five minutes and wiping the progress on it.

Would any one else use that?

It's a good idea ! There is some chars (sometime as easy as 代) which doesn't want to enter in my brain !

I think that's a good idea too. If we do a more advanced rating system (Nick talks about it in the topic "Ideas for making Skritter quicker" at http://www.skritter.com/forum/topic?id=5497921&comments=8 ), then we could possibly put such a button into that system. We'll keep that in mind, thanks for the idea! For now I think I'll lower the minimum interval so that for those kinds of words you can have them studied a little more often. Right now the minimum time between reviews is 10 minutes; let's put that down to 2 minutes. If you keep marking it wrong it will get there.

Sounds like a good idea to me too.