I have problem updating the email optin setting for contacts. Does this call need to be made in the same session as ContactService.add ? Trying to call it after contact has been added is failing silently....
I read a post on stackoverflow.com in which the developer reported success when using 3 methods together in one session (I assume)
FYI we are using FileMaker pro with XMLrpc plugin with success for other functions, so I don't think this is the issue.