Any ideas on why this code would crash (crash location indicated below)?

email is a valid NSString*... ([email protected])

+(void)newContactFromEmail:(DetailViewController*)controller email:(NSString*)emailAddress{
    ABNewPersonViewController *npvc = [[ABNewPersonViewController alloc] init];
    ABRecordRef newPerson = ABPersonCreate();
    [self updateEmail:newPerson email:emailAddress];
    npvc.displayedPerson = newPerson;
    npvc.newPersonViewDelegate = controller;
    [controller.navigationController pushViewController:npvc animated:YES];
}   
 +(void)updateEmail:(ABRecordRef)person email:(NSString*)email{
    **crashes Here**---->>  ABMutableMultiValueRef multiEmail =  ABMultiValueCreateMutableCopy (ABRecordCopyValue(person, kABPersonEmailProperty));
    ABMultiValueAddValueAndLabel(multiEmail, email, kABHomeLabel, NULL);
    ABRecordSetValue(person, kABPersonEmailProperty, multiEmail, nil);
    CFRelease(multiEmail);
}