Yes that worked for my sites too. That took about 2 days to find out!
Now the caption screws up the layout. Instead of wrapping and having each picture in a 1/3 of width box the caption does not wrap and if it is very long the box for the picture is very wide. There are still 3 columns but the columns are even depending on caption length.
So the CSS suggested was not complete. It needs something to force 33% width so the caption wraps.
Also the picture should be top aligned and not pushed up if caption is too long and pushes up picture.
I will have to fiddle with CSS to get a better result with very long captions that are wider than the thumbnails above them.
If you have the CSS answer please give it.