  We study transient charges formed in methane clusters following ionization by
intense near-infrared laser pulses. Cluster ionization by 400 fs ($I=1 \times
10^{14}$ W/cm$^2$) pulses is highly efficient, resulting in the observation of
a dominant C$^{3+}$ ion contribution. The C$^{4+}$ ion yield is very small, but
is strongly enhanced by applying a time-delayed weak near-infrared pulse. We
conclude that most of the valence electrons are removed from their atoms during
the laser-cluster interaction, and that electrons from the nanoplasma recombine
with ions and populate Rydberg states when the cluster expands, leading to a
\textit{decrease} of the average charge state of individual ions. Furthermore,
we find clear bound-state signatures in the electron kinetic energy spectrum,
which we attribute to Auger decay taking place in expanding clusters. Such
nonradiative processes lead to an \textit{increase} of the final average ion
charge state that is measured in experiments. Our results suggest that it is
crucial to include both recombination and nonradiative decay processes for the
understanding of recorded ion charge spectra.
