I'm not able to reproduce this and we haven't heard any other issues about duplicate POSTs. First, make sure you don't accidentally have the same URL set up more than once. Otherwise, this sounds like something that support can help you with, so I'm going to close this issue. Please contact support directly by emailing firstname.lastname@example.org or create an account at Support's JIRA instance at support.atlassian.com. There, you'll get personal service with this issue.