Rated 5 out of 5 stars

This was extremely helpful in restoring the attachment UI of Thunderbird 3.x in Thunderbird 5.0.

There's also a CSS change that's supposed to do something similar, but it wasn't quite what I wanted. You can find the CSS change here: http://kb.mozillazine.org/Thunderbird_5.0_-_New_Features_and_Changes#Attachment_pane_redesign (not my code).

This review is for a previous version of the add-on (0.3).