Bad Behavior is behaving badly with Paypal?

I received the following notice from Paypal.

Please check your server that handles PayPal Instant Payment Notifications (IPN). IPNs sent to the following URL(s) are failing:

http://my-domain-here/wp-content/plugins/wp-cart-for-digital-products/paypal.php

If you do not recognize this URL, you may be using a service provider that is using IPN on your behalf. Please contact your service provider with the above information. If this problem continues, IPNs may be disabled for your account.

Thank you for your prompt attention to this issue.

Thanks,
PayPal

I read on the internet that this could be caused by the Bad Behavior plugin. Do you agree? I installed this plugin about a month ago. I’ve been using the estore plugin for several years. I deactivated the Bad Behavior plugin while I check this out.