If you have the beta test version of firefox then it can be quite annoying when you upgrade to find that most of your addons don't work anymore.
I used to scour the internet for working versions that people had managed to pull from google trunk, but last night I discovered a must have extention which makes all addons work (I never said compatible!) with the latest version of firefox.
The reason addons stop working is the configuration file of the addon stating which version it is compatible upto. So how do they know if it is compatible with the latest version if it stops working as soon as the new version is released? The community of course! but how do they find out if it works?......
They know if it works or not because they use the Add-on Compatibility Reporter.
This tool is provided for users to test addons and then report back to the creator any problems they find with the latest versions of firefox.
Once it is installed it makes all your incompatible addons active again. If you find a compatibility problem you go to the addons tab and click on the new compatibility button and send a report off the problem to Mozilla.
I know this article is based around pagespeed but it will work for any addon that says it is incompatible. I just find pagespeed to go missing for a while each time I upgrade.