Update: I probably won't be able to get FlashChat running again. I downloaded the most recent version (ours was WAY old) and I can't even get the installer to run without fatal errors. Darren's last update was from 2010, and the world has evolved since then. His scripts were always a bit flaky, in any event. I can't get support 'cos his forums are *gone*, and his site has been stagnant since around 2010.
I should be able to trash and reinstall the Ajax Chat applet (the one that was CHAT2). I know it's not as pretty, but it's more solid AND it's been continuously updated to keep pace with the PHP/MySQL versions. I did some significant changes to the one we're running, and I'll have to tweak it as I go along over the next couple of weeks to remove the bugs or add some handy features back in.
When I switch Ajax Chat to the newest version, it'll probably blow the forum away for up to a half hour. If you see error messages, just come back a bit later and I'll have it up once more.