Im using cimy extra fields in Brazilian Portuguese.
When I choose to display the First and last name fields on the registration page, they would appear in english for the user.
Looking at the code, I found that on line 888 of cimy_uef_register.php you would print the label whithout any localization function:
$obj_label = '<label for="'.$unique_id.'">'.cimy_uef_sanitize_content($label).'</label>';
I changed that to:
$obj_label = '<label for="'.$unique_id.'">'.__(cimy_uef_sanitize_content($label), $cimy_uef_domain).'</label>';
and it worked fine.
Its not a definitive fix, it worked for me. I hope you can have a look on that.