Unfortunately, this plugin didn't work for me. When activiated, my thumbnail galley was simply vertically titled and looked horrible.
Turns out the gallery worked fine when I was logged into WordPress. But as soon as I logged out, I had the same issue (vertical tiling).
Looking at Firebug, I noticed that the nextgen gallery CSS was not getting loaded, thus the styling was no good. Ah ha. So I disable this plugin, and everything works fine again.
I've deleted this plugin and will do it the old-fashioned way -- editing my functions.php file to dequeue the nextgen gallery stuff.