Suporter stats still missing, ads Still running on upgraded sites, Paypal IPN

With the last two updates of Supporter, I've had no stats. While my supporter blogs were billed and paid through paypal (payment went through), there is no record of them in my supporter stats. Further, they continue to have ads running on their blogs, even if I manually go in and upgrade them.

I also just received an email from PayPal saying, "Please check your server that handles PayPal Instant Payment Notifications (IPN). IPNs sent to the following URL(s) are failing" I have no idea what that means. The payments did go through and I have set up the account per Supporter guidelines.

Help is appreciated.

Thanks.