When I perform a full edit of my post it changes the post so it was posted by "Unregistered" rather than me. There seems to be no way to undo this once it has happened. I haven't yet tested if this happens with normal members but I will investigate it.
Either disable the admin post edit plugin or upgrade to the newest version of it.
Couldn't fnd an update on zinga burga's site (or the plugin at all for that matter) and I couldn't find it using the mod search on the main MyBB site. So I guess I'll have to disable it. Thanks for the heads-up.
Ask on Zinga's site, we can't really help you here because we didn't write the plugin.