The root issue is [bug 9665](http://d.puremagic.com/issues/show_bug.cgi?id=9665). From 2.063, by the introduction of qualified constructor, the importance of bug 9665 has increased. However to fix it properly, implementing qualified postblit is necessary.

I've been working for that during 2.064 development, but unfortunately it won't meet the deadline before release...