  We study exceptional modes of both the Wilson and the clover action in order
to understand why quenched clover spectroscopy suffers so severely from
exceptional configurations. We show that a large clover coefficient can make
the exceptional modes extremely localized and thus very sensitive to short
distance fluctuations. We contrast this with the case of the Wilson action
where exceptional modes correspond to large instantons. These modes are broadly
extended and suffer much less from discretization errors.
