Usually A,B,C from Div1 are C,D,E from Div2. I solved such a shared problem during a contest and later I wanted to read my code again. So I went to "PROBLEMSET" and chose that task (it was green!). But page with statement didn't show my submission. It seems my submission is attached to div1-version of problem and "PROBLEMSET" page shows shared tasks as div2 ones. It is a bit uncomfortable.
Later I found my code (I chose right d1-contest from list of all contests) and from curiosity I tried to submit my solution by page with d2-version. As I've expected it gave me +1 to problemset standings (number of solved tasks).
I think it is something to be fixed.
Btw. thanks Mike (and other people working on CF) for such an amazing platform! :)
Same with the problems from CF solved in a group mash-ups. They are also green, but can't be found on "My submissions" in div2 and div1 problem page.