Finding incompatibility in Firefox addon

I have an custom addon developed for our workplace (using the add-on SDK) that was originally developed for FF4.

When FF5 came out all I had to do was rebuild the XPI. FF6 was able to use the same XPI.

Now I'm trying to get it running in FF7, and it's not working. I get a "this add-on is not compatible with Firefox 7" when trying to install it.

I've read this blog post: http://blog.mozilla.com/addons/2011/07/19/firefox-7-compat-looking-to-8/ And from what I can tell none of the changes affect my add-on.

Also running this开发者_JS百科 validation test https://addons.mozilla.org/en-US/developers/addon/validate Yields no errors or warnings.

Any clue on how to find out what makes FF7 think it incompatible?

You should use the newest version of the Add-on SDK to rebuild your add-on. Right now, the latest version you get offered on the SDK download page is Add-on SDK 1.1, released on September 13th. It will mark add-ons compatible with everything up to Firefox 8.0a1. You are most likely using an older version, e.g. Add-on SDK 1.0 would only mark add-ons as compatible with Firefox 7.0a1.