Paypal IPN Issue

I keep receiving notifications from paypal stating the following:

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

www.mojolands.com/joomla16/index.php?opt...ent_method=os_paypal

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.



I'm not sure what is going on. I suspect that the URL is incorrect as we have no "joomla16" folder in our directory. We did away with it after we launched the site (changed the name). Any suggestions?

Thanks.

Maybe that IPN message was created when you develop your site in Joomla 1.6 folder ?

Regards,

Tuan