Okay. AMO (addons.mozilla.org) is not being helpful. I have no idea what’s been going on. It’s been over a month since the addon has been uploaded and I have not gotten any emails from them. I’ve already contacted them SEVERAL times and I have not gotten a response.
Any problems you are having now are mainly because they aren’t pushing out the versions. I’m apologize for this problem and I’m deeply angered that developers are receiving this kind of support right now.
Here’s a new build that updates Postbox compatibility. I’ve been way too busy with projects to fix any other problems that might be going on with the recent nightlies (I knew this was gonna happen though).
You can get the build here.
This version has been released on AMO already.