Affirmative answers to two
questions of Dade are given: 1. If the 1-component R1 of a ring R graded by a finite
group contains only finitely many central idempotents then so does R. 2. If R is a
ring fully graded by a finite group G and if S is a G-invariant unitary subring of R
then, for every block idempotent a of R, the block idempotents b of S such that ab≠0
form a single G-orbit.