OK, after following your instructions, now I'm successfully seeing the site in Chrome, but that does nothing for potential visitors with the "wrong" browser. (Safari still doesn't work.)
Seems like a lot to ask of visitors.
I'll approach the web site owners about looking for another gallery solution.
Upgrading the plugin didn't make any difference in Safari.
The default setting on these browsers is to reject flash? Why does youtube work?
Could it be a theme conflict?