Security warning on return from Authorize.net

I'm using Authorize.net to process payments. Customers leave my site (which does not have SSL) and go to authorize.net to process the payment. After submitting the payment, and on the screen that says "This page will automatically redirect you back to ...com for your order confirmation details. If you are not redirected within 5 seconds...", a security warning box pops up that says "Although this page is encrypted, the information you have entered is to be sent over an unencrypted connection and could easily be read by a third party. Are you sure you want to continue sending this information?"

I'm assuming that this happens because authorize.net is sending the customer information VIA a hidden form from their SSL site to the non-SSL store for processing.

1. Is that correct? and,
2. Is there anything that can be done to eliminate this message other than get SSL on the store site?

Thanks

You will need to get SSL on the store site. It's very inexpensive these days, and gives your customers the added peace of mind that you actually take security seriously.