Why isIdentical instead of equals?

[nicknewman]

I understand that the EJB spec says that you have to use isIdentical instead of equals to compare two entities, but I'm curious about why this is. After all, if you have an isIdentical method, can't equals be implemented along the following (pseudo-code) lines?

public boolean equals(Object o) {
 if( o is an instance of an EJB )
 return this.isIdentical( (cast-to-EJB) o);
 else
 return false;
 }

There must be a good reason. I just can't think what it is!

Thanks,
Nick