Hopefully this might just help someone out – to many people, it’ll seem obvious, but when you’re getting frustrated, you tend to overlook the obvious…

When you’re editing WordPress themes, and you’re including content from a separate database, make sure WordPress is able to connect to the database its data is stored in at the end. I had a custom header and footer set up, and utilised a database connection to get page data. After some investigation, I realised that WordPress needed its database connection back – doh!