There's Always Something, Even in Quantum Cryptography

Technology Review has a post on the ways errors in practice might create loopholes in quantum cryptography:

When it comes to secure messaging, nothing beats quantum cryptography, a method that offers perfect security. Messages sent in this way can never be cracked by an eavesdropper, no matter how powerful.
At least, that's the theory.

Actually, I was also bemused by the fact someone is actually creating and selling quantum cryptographic systems.  My grasp of modern physics ceased with the old solar system model of the atom, with the orbiting electrons.  Quanta and strings are a couple generations beyond me.