my Gallery permalink option reads:
"Activate permalinks: When you activate this option, you need to update your permalink structure one time."
Neither checking nor unchecking that option affects the issue. I do not see a "Day and name" sub-option. My Gallery/Options/Slideshow tab is curiously blank(!).
The error that has been coming up for me is from nggwidget:
'<a href="http://www.macromedia.com/go/getflashplayer">Get the Flash Player</a> to see the slideshow.</div>'
updating swfobject.js has no effect.
IE6 shows an additional JS error:
"'J.parentNode' is null or not an object"