Late Inflation and the Moduli Problem of Sub-Millimeter Dimensions

We consider a recent model with sub-millimeter sized extra dimensions, where the field that determines the size of the extra dimensions (the radion) also acts as an inflaton. The radion is also a stable modulus, and its coherent oscillations can potentially overclose the Universe. It has been suggested that a second round of late inflation can solve this problem, however we find that this scenario does not allow for sufficient reheating of the Universe.