  Qubit loss and gate failure are significant problems for the development of
scalable quantum computing. Recently various schemes have been proposed for
tolerating qubit loss and gate failure. These include schemes based on cluster
and parity states. We show that by designing such schemes specifically to
tolerate these error types we cause an exponential blow-out in depolarizing
noise. We discuss several examples and propose techniques for minimizing this
problem. In general this introduces a tradeoff with other undesirable effects.
In some cases this is physical resource requirements, while in others it is
noise rates.
