CREDITS not working

[SRLtd]

Can anyone help, the credit system is not working on my Classifieds.
I have entered the correct IPN url and made sure it is turned on,
but the credits are not showing on the classifieds.

Any help would be appreciated:)

[SMFHacks]

Check that you can access without error the following page
http://www.yourforum.com/classifiedsipn.php

Or if you are using SMF 2.0.x
http://www.yourforum.com/classifiedsipn2.php

If you get a server error change the permissions on the file to at least 755