OK - I’ve ruled out DNS and ISP. I’ve also had several associates (some in different states) try this out, and ALL of them are witnessing the same behavior.
Please try this again, because sometimes (less than 10% of the time) it works as expected, but the rest of the time, the incorrect behavior shows up.
Again, to make sure we are talking about the same thing: When the tweet button is pressed, a popup shows up, with preloaded tweet and URL. If someone presses ‘tweet’ on the popup, the window gets replaced with a second tweet window, that has the preloaded text, but not the URL. If the person presses tweet again, there would be two tweets in their timeline (one with link, one without). If they simply kill the window at that point, they will have only one tweet in their timeline, but that is not the correct behavior.