When we upgraded to Phalcon 2.0.0 all of our classes that implemented the InjectionAwareInterface not require the type declaration in the setDi method. So previously the function declaration was:
public function setDi($di) { $this->_di = $di; }
This no longer works and now requires the type declaration Phalcon\DiInterface on the argument. So the new declaration must be:
public function setDi(\Phalcon\DiInterface $di) { $this->_di = $di; }
I am not sure if this was by design or a bug as none of the other documentation or items in teh changelog mention this major change.
Thanks