The Twitter Help pages says "You can only send a direct message to a person who follows you" (btw don't miss the style attributes in the source of that page). Ok. I currently have 247 followers and am following 57 persons. But the dropdown menu in the DM page lists only 84 persons I can DM... 84, not 247.

It's even more complex than that: Doug Schepers (shepazu) for instance is following me, I can DM him, but if I query the list of my followers through http://twitter.com/statuses/followers.xml , shepazu is NOT in the list.

And of course, there's the issue I filed a few hours ago.

All in all, implementing a software above Twitter is a lot of fun, but also a lot of pain.

All clues highly welcome....