Known Issue: Problems with Socialize service.
Thursday, December 2, 2010 | 8:43 PM
Issue: Posts being sent by the Socialize service to Twitter are not always being delivered, and attempts to connect your Twitter account in Socialize resulting in server errors. We are investigating the problem and will update this post as soon as we have more information.
Update (6:54pm PST 7-Dec): The issue has been resolved; you should now be able to connect your Twitter account in Socialize without any problem, and Twitter delivery is working normally.