Installed this today, seems to be working ok in it's default state. However I noticed that it is quite slow displaying each thumb, presumably because it is creating them on the fly.
However when I turn on 'Enable thumbnail caching', instead of displaying the thumbnails it shows a purple 'barber pole' animation in place of each thumbnail. This animation goes on forever. If I FTP into my server I can see that that the plugin is not creating a 'thumbs' folder. I also tried creating my own 'thumbs' folder and giving it 755 permissions, but the barber poles still appear. Any ideas much appreciated!
On an unrelated note, do you anticipate any problems using this plugin to display the same gallery on several different pages?