As is usually the case with the WWW, I've discovered my amazing pop-up window tool tips don't work consistently across platforms. On a Macintosh (any browser) the pop-up appears just fine, but when you move the mouse off of the link, the window stays there. It will only disappear if you bring focus back to the main window, mouse back over the link, then mouse out. Rather than attempt to fix this, I will let Mac users get an extra puck-mouse workout as they click from window to window. In the meantime, they can take solace in the fact that at least their computer in the midst of one of its hourly system crashes.