We investigate current problems in obtaining reliable ages for old stellar
systems based on stellar population synthesis modeling of their integrated
spectra. In particular, we address the large ages derived for the globular
cluster 47 Tuc, which is at odds with its color-magnitude diagram (CMD) age
. Using a new age indicator, H gamma (sigma <130), which is particularly ef
fective at breaking the degeneracy between age and metallicity, we confirm
the discrepancy between the spectroscopic age and the CMD age of 47 Tuc, in
that the spectroscopic age is much older. Nebular emission appears unlikel
y to be a source for weakening the observed Balmer lines. We then explore a
number of key parameters affecting the temperature of turnoff stars, which
are the main contributors to the Balmer lines for old metal-rich stellar p
opulations. We find that <alpha>-enhanced isochrones with atomic diffusion
included not only provide a good Dt to the CMD of 47 Tuc but also lead to a
spectroscopic age in better agreement with the CMD age.