I got an email this morning (April 2) telling me to pass along this notification:

If you want to access your outstanding invoices list under Make A Payment on Your Account, please hold off until April 3rd 2009 to do so. We are in the process of moving our billing data to a new accounts receivable system so our Main Frame is currently showing all invoices as PAID online even though this may not necessarily be the case on your account.

All the data should be refreshed by April 3rd once the internal transfers are completed. We apologize for the temporary inconvenience.

We will update this post if any of this information changes. We appreciate your patience!