Have you been tweeting from your blackberry? If so then you may find that one of the popular applications is not working. The reason for this is because Twitter suspended the application. UberTwitter is supposed to be working on a fix.
UberTwitter is a very popular application. There are thousands of user that utilize this application ever day. I am sure that Twitter is going to get things smoothed over with the relationship as soon as possible. Many people have been upset because of not being able to use UberTwitter.
If you can not access your account through this application then you can use the official application. It may not be as cool as the one Twitter suspended but it will help until things are fixed. The said reason for suspension is trademark infringement. UberTwitter is supposed to be changing its name to UberSocial.