Sorry for repeating myself, but I was about to ask for this without even remembering that I had already asked in the past
When scrolling through the pages to view problems I haven't solved often there are pages where I have solved most on the page, it would be so nice if I could just see the ones I hadn't solved.
I'm not sure what you're using to display the tables but I'm sure it must be easy to only show unsolved ones - in the worst case I could write a script for myself if you provide some sort of feed with all that info 
(If its just an SQL query this could be added in minutes, even if you don't provide a button to click but just an extra variable in the query string..)