This has happened to me more than once. If it matters I am using Firefox.
I compose a reply and when using the "Add Reply" button the screen will show a loading progress bar and then after that the post is not posted. I am making it a habit now to copy all replies before posting. This should never need to happen.
I hope Jive can get these things fixed or FileMaker can find a new platform. Is this really any better than what we had before? I do not recall that there were this many issues in usability before.