[Evolution] Google Contacts duplicated?

[Oon-Ee Ng <ngoonee talk gmail com>]

Hi, I've not used the google contacts feature before, the last time I
tried it last year it didn't support birthdays so was a no go. I
settled on mobical.net (now everdroid.com) and syncevolution to get my
contacts synced to Google Contacts.

I just tried Evo's google contact sync again, and this time I got
birthdays, but also duplicate contacts. Every contact is duplicated,
but in contacts which have a birthday, one of the duplicates has it,
one doesn't.

I'm not sure whether the contacts are 'echos' of previous syncs I've
done. Removing various files from .local/share/evolution doesn't seem
to change things (where are the google contacts stored anyway?).
Browsing my google contacts through the gmail interface doesn't show
any of the supposed duplicates, oddly enough.

I'd really rather not have to manually delete contacts (and then maybe
find that they disappear on google for good), so could someone please
confirm this behaviour? Is there a 'hidden' google contact book which
is not accessible through the gmail interface?