I would guess you had some sort of
search / filter in place, so what was left had no marks.

ALWAYS LOOK at the status line next to Kovids name:
Code:
[#####] = the size if the Library in all cases
[nn of #####] = the number of results from a search
[ nn of yyyy, 1 selected, ##### total] A VL is in place and it has yyyy members, AND nn items met your Search, you have 1 highlighted out of the fill Library #####