I was surprised not to find other posts about this (or issues on the tracker as far as I can see).
After clicking on view/grade all submissions there is a useful filter at the bottom which lets you see only work which requires grading. I have found that does not always work. Weirdly if I log on to two systems I can often change the filter on one (on which it works) and refresh the page on the other and fidn the filter applied even though the drop down itself will not work on the second system. I am guessing the setting is stored in the database and not locally.
I have not duplicated what I am about to say but at the moment the drop down works until I click the minus sign to shrink one of the columns in the table (file submissions). If I then click the plus sign to get the column back the drop down filter at the bottom works again. When it fails to work I get no JavaScript errors.
I did notice that when shrinking the columns I often see errors even though it works fine. Perhaps those errors are stopping the later JavaScript?
Anyone else experiencing this? I am using Firefox and it happens with version 10 and 16 at least.