Pop ups work fine. Each one must be closed individually before the next one will open. No security warnings. If the viewer clicks on the next thumb the pop up returns to the front of the screen with the first image awaiting closure.

Safari Version 2.0.4

However, in Firefox the popup goes behind the browser window and does not return to the front if the surfer clicks the main page again. 2.0.0.3

Hope the helps...btw..nice looking page. Very clean.