i18n - Synchronize translations

Hi people, when i synchronize some fields of a content type there is a bug in node translation.

IE:
node/3 -> Spanish
node/4 -> English
node 4 is the english version of node 3

If i update any of them, the other will get the meta tags reseted to default value.

Hope anyone can help,
in meantime, i unselected all sync fields.
Thanks for your time.