I received this email from Dropbox recently
Last year, we announced version 1 (“V1”) of the Dropbox API. V1 introduced a number of new features including mandatory OAuth authentication which is more secure and gives Dropbox users control over how apps access their data.
As part of the V1 announcement, we also mentioned that we’d be phasing out version 0 (“V0”) of the API. While the majority of developers and apps have already moved to V1, we’ve noticed that your app, ‘Password Safe Pro’, has made calls to the V0 API in the last 90 days.
We will be retiring version 0 on December 1st, 2012. After December 1st, the V0 API will be shut down and applications using it will no longer be able to make calls. Please plan to migrate your app before this date. We understand that migrating to V1 requires work on your part, so we’re providing several months notice before making this change. You can also find a more detailed explanation of the changes in V1 in our migration guide.
What exactly does it mean to you? If you are using a version of Password Safe that is earlier than version 22.214.171.124 then Dropbox functionality will cease to function. You should update to the current version if you want to keep using Dropbox.