The problem, as described by WebWorkerDaily:
"Though the blog post says there’s no magic number, quite a few Twitterers - including some heavy participants - report hitting the limit at 2000. Some have been trying to get the attention of Twitter management to discuss this for days, with little or no result. It’s reminiscent of Twitter’s attitude towards making money from the service, which amounts to “we have a plan, but we won’t tell you,” or to fixing issues, which seems to be “we’re working on it, leave us alone.” In a world of Web 2.0 openness, Twitter seems to be carrying traditional business values of secrecy a bit further than most."It's all too easy to keep your users in the dark. It takes real vision to open up and keep your users in the know.