Rated 5 out of 5 stars

Fantastic!
Note: After running the install, when you add the buttons be sure to select the icons for "REAL Previous" and "REAL Next"!
The OLD versions of Prev-Next will be in the list but you need to ignore them or you will be adding the wrong buttons. (Probably what the other review did without knowing it.

QUESTION:
Will they ever make this a STANDARD part of the Thunderbird. The old Prev-Next are useless...