Description:
------------
In proper OOP, i should be able to define an interface, and have a class 
or abstract class implement it.

If I create a class (or abstract class) which calls upon the interface 
in a method signature, everything is ok.

However; if I extend the aforementioned class (or extend unto an 
abstract class), and I call upon the class which implements the 
interface, my compilation fails.

Even if I provide a method in my interface and implement it in the class 
which uses the interface, it still fails.

I have been able to reproduce this in both php 5.2.10 and 5.2.6 
(personal and work servers, respectively)

Reproduce code:
---------------
interface Validatable {};

class Form implements Validatable
{
}

abstract class Validator
{
 abstract public function Validate( Validatable $v );
}

abstract class Form_Validator
extends Validator
{
 public function Validate( Form $f )
 { // do something in here...
 }
}

Expected result:
----------------
I should see nothing.
OR -- if i look in memory, I should see that my Form_Validator has a 
Validate method in it.

Actual result:
--------------
Fatal error: Declaration of Form_Validator::Validate() must be 
compatible with that of Validator::Validate() in ....