Ok, here's the info from the admin overview page:
Zenphoto version 1.3.1.2 [5831] (Official Build)
Current gallery theme: Stopdesign Theme
PHP version: 5.3.8
Graphics support: PHP GD library bundled (2.0.34 compatible)
PHP memory limit: 128M (Note: Your server might allocate less!)
MySQL version: 5.5.17
The server is Windows Home Server 2011 running IIS version 7.5
Apparently the following plug-ins are active:
class-video v1.3.1
filter-zenphoto_seo v1.3.1
hitcounter v1.3.1
security-logger v1.3.1
tiny_mce v1.3.1
zenphoto_news v1.3.1
zenphoto_sendmail v1.3.1
I'm not aware that I've installed any so I assume these are installed by default.
Interestingly, I had assumed I had the latest version because when I click the link to check for an update it tells me that I have the latest version. I can see now that I don't, so I will sort that out when I have the time. However, I'd still like to know what has caused this as I haven't changed anything on Zenphoto for a very long time, and it was working relatively recently. It's for this reason that I didn't report it as a bug - I assume something has changed on the machine's setup.
Thanks
John