Although I didn't have problems with the former, this header is good too, thanks. However, (at least on my screen) there is one issue : clicking on problem ID just darken the top and borders of the screen, but pop-up nothing. (I'm using chrome 20.0.1132.57 m on windows). I think that for some reasons the pop-up appears "under" the page.
So now problems ratings change accordingly to the estimated strength of the solvers and maybe the time they used. Sounds good. I'm curious to know the algorithm
Concerning fractional kyus/dans, I prefer this way because I see how close I go to one level or another. But integers would be fine too, not a big deal.
I have another request : I loved the "back" ("next") button which allowed to jump to the previous (next) problem ordered by date. It's much easier to solve a series of new problems with these buttons. If you can add them (at least the "back" one), then the interface would be perfect to me.
And I have a final request : it would be really nice to have a button on top of the screen to remove a problem from our favorites. The "add to favorites" button could just turn into "remove from favorites". I tend to add as favorite any beautiful problem that I'm unable to solve after 10-15 minutes, so my list is quite crowded and this button would really help to clean ^^
Thanks in advance,
Piccolo / Benjamin