Weird problem on host, not on localhost

Okay. I've been working on this project for a while now, and have now run into a hitch – it's running perfectly fine on my localhost running WAMP – PHP 5.4.3, Apache 2.4.2, MySQL 5.5.24
When trying to put this onto a webhost for testing, it breaks. I've checked and doublechecked the config.php, coreclass.php and such, and can't see anything obviously wrong.
The full project can be found here, on Github: https://github.com/langbakk/persdbnew_kvarteret if anyone want to take a stab…
Weird problem on host, not on localhost

See original post by PoPSiCLe