Nette framework (http://nette.org) has got own Nette\Object as a base of other objects. It also rewrite the default __get method in PHP object but it uses definition with pointer:
Doctrine Common creates Proxy classes with __get method too but not with reference. It causes an error using strict warning:
The problem is in ProxyGenerator. Locally I've patched it in my Doctrine repository clone but don't know how to resolve it globally.