I run Windows 7 and Thunderbird, recently updated to version 31.5. Spotted problem when I tried to use accents in the text of an e-mail, and found that Zombie Keys was not working as normal. Investigated all the add-ons in Add-ons Manager and found that the 'compatibility' key for each one comes up with the message 'This add-on no longer works'. System is set to update add-ons automatically and all of them appear to be up to date.