Рейтинг 4 из 5 звёзд

Since yesterday I now only have a black oblong in place of the buttons in top right, still work okay, just cant see them...

Это отзыв для предыдущей версии этого дополнения (2.24.1). 

Hi Richard, It has been fixed and new version has been submitted to Mozilla. Now it's in verification queue and it should be available in few hours.

Till then you may apply workaround:go to Preferences->Advanced tab->(button) Settings editor->type: "mail.tabs.drawInTitlebar" and set its value to "false"

or download fixed version form here:
https://addons.mozilla.org/thunderbird/downloads/file/228971/ms_office_2003_jb_edition-2.24.2-tb.xpi