I have set up my "New Tab" page to show 8-12 different links (I don't remember exactly). When I opened it up today, though, I could only see 4 of them (the top row). To be clear, I'm NOT talking about the problem with the missing thumbnails (a black "screen"). The missing tiles are missing completely. There aren't even black screens. The missing ones pop up in the background when I go to add a new tile - I noticed because I thought they had disappeared altogether so wanted to re-add them - but disappear as soon as I release the mouse button to add that new tile. So Firefox hasn't forgotten them altogether. It just isn't displaying them. At first I thought they might just be "down below", but there is no vertical scroll bar showing up on that tab either, so that's not the answer. It's almost as if the vertical scrolling has been shut off for some reason. But that's just a wild guess from a non-programmer. My largeish screen resolution could be a factor, but I haven't changed it a long time, so it isn't the immediate cause of the problem. How can I get my tiles back? :)