Id given seems to be invalid

Id given seems to be invalid

Hi there.

I'm using PHP SDK for creating a lead from my website form. It's working but sometimes I get the response:

(
            [code] => INVALID_DATA
            [details] => Array
                (
                    [id] => 3220979000034212261
                )

            [message] => the id given seems to be invalid
            [status] => error
        )

I'm not passing any "ID" tough... It doesn't happen all the time. Does anyone know something about it?

Thanks!