getting error for paypal-ipn

[peter888]

I installed paypal-ipn and ccgv, sometimes, After I clicked the check out confirmation, go to the following page.

 

https://www.paypal.com/cgi-bin/webscr.

 

sometimes, getting following error:

 

 

"

Error Detected

This invoice has already been paid. For more information, please contact the merchant.

"

 

the reason is I did not buy the items, but it has an error detected. anyone knows what wrong? do i need re-install paypal ipn?

 

 

Thanks a lot