  A detailed study of critical spreading in the one-dimensional pair contact
process is performed using a recently devised reweighting method. The results
confirm the validity of a generalized hyperscaling relation among the
(nonuniversal) spreading exponents, and support the assertion that the critical
point location does not depend on the particle density \phi. It appears that
the exponents z and delta+eta, once thought to be invariant, exhibit a
systematic dependence on \phi.
