Admin privileges dialogbox a different language when running an installer?

[OzyOly]

For some reason, when OSX asks for my admin password when installing a new programme, it asks me in a different language. I've checked my preferences and I'm definitely set to British English. I've also repaired permissions.

Any idea? The rest of the install process is in English...

 

[OzyOly]

Looks like I'm to have to call Apple tech support for an answer then. 🙁