With the recent launch of @Twitter's @Anywhere API there have been a number of developers having issues with the follow button and the Tweet Box not working. This stems mostly from a bug where new applications created on dev.twitter.com would default to read only access.
If are having problems using @Anywhere try this simple step by step guide.
Check that your application has "Read and Write" as the "Default access type". If not edit your application settings so it does. You can do that on https://twitter.com/apps.Check that your @Twitter account's access token for said application has "read and write access". If not revoke access and re-authorized from the website you are testing @Anywhere from. You can find out the access type on https://twitter.com/settings/connections.Delete your cookies. Specifically the "twttr_anywhere" cookie for the domain hosting the @Anywhere code. You can read more about clearing your cookies https://www.google…
* In the web interface new mentions are only replies if they start with @screen_name. By pushing @screen_name further along in the string your followers who do not follow @screen_name will still see the status.