Valrus, I think you're right, but I'd have to dig out my Little, Brown Handbook to be sure. (That's a very good reference book, by the way, and the title refers to authors not physical characteristics)
Anyway, the currently accepted standard is to have the punctuation inside the quotes, AFAIK. But standards change to reflect the times. So when everyone uses words or does things a certain way, even the 'standards' groups must adapt to conform to popular opinion at some point. For example, think of the sheer number of words associated with computers that have been coined in the last decade. The dictionary committees eventually put those words into print since there is a common usage and agreed meaning.