  We have obtained velocity dispersions from Keck high-resolution integrated
spectroscopy of ten M31 globular clusters (GCs), including three candidate
intermediate-age GCs. We show that these candidates have the same V-band
mass-to-light (M/L_V) ratios as the other GCs, implying that they are likely to
be old. We also find a trend of derived velocity dispersion with wavelength,
but cannot distinguish between a systematic error and a physical effect. Our
new measurements are combined with photometric and spectroscopic data from the
literature in a reanalysis of all M31 GC M/L_V values. In a combined sample of
27 GCs, we show that the metal-rich GCs have *lower* M/L_V than the metal-poor
GCs, in conflict with predictions from stellar population models. Fragmentary
data for other galaxies support this observation. The M31 GC fundamental plane
is extremely tight, and we follow up an earlier suggestion by Djorgovski to
show that the fundamental plane can be used to estimate accurate distances
(potentially 10% or better).
