I went back and tried it again and the same thing happens to me.
I generated my javadocs, and to my great surprise, I was short of one class, too. But then I looked closer and found the "missing" file: in javadocs HTML package display, the exception classes are listed separately, and in the other window, the interfaces are also listed separetely, and that's what I didn't spot when I looked at it originally. I am almost sure you have the same problem, guys. Or rather, there is no problem at all.