I haven't used
authorize.net, but basically, if this is an asynchronous processor (eg, the user is sent offsite to an
authorize.net page to input their CC details), then PCI-DSS is not a concern for you, as you are not handling the CC transactions yourself. PCI-DSS compliance is one of the main reasons to 'outsource' CC processing to an async processor who handles card details for you. One example of a processor for GetPaid that does this is the getpaid.pxpay plugin, which uses PaymentExpress to handle the CC details (
http://www.paymentexpress.com/index.html).
regards,
Darryl Dixon
Winterhouse Consulting Ltd
http://www.winterhouseconsulting.com