You can rescreen them, if you click on the little eye in the original comment (points up), and once greyed out, the comment is RESCREENED. Have to be quick about it, though!

Or, you click on the little box at the end marked 'Select', click on all comments that apply, and go to the bottom of the page, where it says "Mass action on selected comments" and pull down the menu, and choose "Screen".

*g*