I am using thunderbird 3.1.4 and gContactSync 0.3RC1.
In thunderbird, I have several address books, some have names in English, and some have name in Traditional Chinese.
I have a new gmail account, so the contact is totally blank.
First, I set up several groups and have one-to-one maping to the address books in thunderbird.
I found that when the groups in gmail contact are in Chinese, synchonization will not work.
Then, when I change the group name to English, it works perfectly.
It's not a big problem to change the group name,
but if you have time, please fix this issue.
Good job.