Rated 1 out of 5 stars

AVOID THIS JUNK,

Zindus appeared to work nicely. Then it quit working. Unfortunately IT WIPED EVERY SINGLE POSTAL ADDRESS FROM BOTH GMAIL CONTACTS AND THE THUNDERBIRD ADDRESS BOOK.

The only extension that seems to properly sync gmail contacts and the Thunderbird address book is gContactSync available at https://addons.mozilla.org/en-US/thunderbird/addon/8451

This review is for a previous version of the add-on (0.8.10). 

RPG, there are no outstanding bug reports along the lines that you describe. With luck there will be an alternative explanation. If you file a bug report we can get to the bottom of it: http://zindus.com/i/reporting-bugs