I just sent a group of messages to Twitter and the only thing that got posted was the shortened link.
This happens only sometimes, though, and I can't find a pattern that points to the issue. The character counts are fine, too. The only thing different that I've done is to send 10 tweets in one burst because we've been timing our articles for releases on the hour instead of spreading them throughout the day (I have no control over this). What might be the issue?