  PG 1115+080 is a quadruply lensed quasar at z=1.72 whose image positions are
well fit by simple models of the lens galaxy (at z=0.31). At optical
wavelengths, the bright close pair of images exhibits a modest flux ratio
anomaly (factors of ~1.2-1.4 over the past 22 years) with respect to these same
models. We show here that as observed in X-rays with Chandra, the flux ratio
anomaly is far more extreme, roughly a factor of 6. The contrasting flux ratio
anomalies in the optical and X-ray band confirm the microlensing hypothesis and
set a lower limit on the size of the optical continuum emission region that is
\~10-100 times larger than expected from a thin accretion disk model.
