С ()-form у автора, как я понял, как раз все в порядке. Что гласит стандарт 2003 про вариант без скобок? в 98 написано (5.3.4 [15])

— If the new-initializer is omitted:

— If T is a (possibly cv-qualified) non-POD class type (or array thereof), the object is default- initialized (8.5) If T is a const-qualified type, the underlying class type shall have a user-declared default constructor.

— Otherwise, the object created has indeterminate value. If T is a const-qualified type, or a (possibly cv-qualified) POD class type (or array thereof) containing (directly or indirectly) a member of const-qualified type, the program is ill-formed;