Currently it seems to be set to 5 Columns, yet there is nothing in the admin which allows one to change this. Ive looked in the script as well, but came up empty. Would someone please help?? Thanks!
Nevermind what I said prior. The thumbs (I just checked the Beta 2 demo) don't have a table; they are therefore dependent on how wide the window and parent objects are. Consequently, it fits as many across as possible automatically. This is a function of the CSS, not PHP, so there's currently no way to limit the number of thumbnails in a row, to my knowledge.
Just edit gallery.css, add a width attribute to #wrapper. You can change the width of the gallery, and the thumbnails will automatically flow to the size of the container.