Thank you, acrylian! Oddly enough, it works if I rename the folder back to /zenphoto and change the .htaccess back to /zenphoto, but stops working again if I rename the folder and .htaccess to -anything- except /zenphoto. Is there more than one area in .htaccess that I'm not seeing where I have to change the folder name?
I shall update then, thanks! Sorry, I am not terribly familiar with zenphoto yet: how do I go about updating it?
Thank you for your help so far!