A Visible clause in the Ace which names a class (or a feature in its
export subclause) is case-sensitive if the name is enclosed in double
quotes, but should not be since it does not refer to an outside
element.  The compiler incorrectly reports a VD25 violation.  In the
case of a feature, the compiler thinks the feature is missing so it
dies (a previously reported bug).

Discovered in Release 3.2.2.