Proposed resolution (August, 2010):
Change 7.6.2.2 [expr.unary.op] paragraph 3 as follows:
...If the operand is a qualified-id naming a non-static member m of some class C with type T, the result has type “pointer to member of class C of type T and is a prvalue designating C::m; the program is ill formed if C is an ambiguous base (10.2) of the class designated by the nested-name-specifier of the qualified-id. Otherwise...
Change 6.5.2 [class.member.lookup] paragraph 13 as follows:
[Note: Even if the result of name lookup is unambiguous, use of a name found in multiple subobjects might still be ambiguous (7.3.13 [conv.mem], 7.6.1.5 [expr.ref],7.6.2.2 [expr.unary.op],11.8.3 [class.access.base]). —end note]...