I have yes. Emailing the file to an address associated with the Kindle is also a standard way to upload a book. That's why I was thinking that this must be some sort of bug. BTW I tried to upload Pride and Prejudice.

Might be late / irrelevant but a while back amazon was failing to convert anything i emailed to my kindle and it turned out to be that i wasn't specifying a subject line in the mail. once i did that the very same files started working.