CiviCRM Community Forums (archive)

I could use some help on this, and I can't find anything on point in the forums (my apologies if it's in there somewhere).

I've been having problems with Paypal Website Standard single transactions not posting as "completed" in CiviCRM. The transaction is complete in Paypal, and the money is moved, but I have to go look in CiviCRM for pending transactions listed as incomplete and check them against completed Paypal transactions.

I'm using CiviCRM 4.1 with Drupal 6.25, having upgraded both over the years. This is a multi-site setup, where Drupal and CiviCRM use separate databases but with a single codebase.

Paypal's IPN log shows that the return URL is this:
www.[mydomain].org//users/home/[myusername]/domains/[myprincipaldomain.org]/web/public/sites/all/modules/civicrm/extern/ipn.php?reset=1&contactID=[number]&contributionID=[number]&module=contribute
and that the response is a 404 error.

My Drupal log shows the error with the offending url, only without the double slash shown above.

If I enter the url above myself, I get a page not found error. if I try
www.[mydomain].org/sites/all/modules/civicrm/extern/ipn.php?reset=1&contactID=[number]&contributionID=[number]&module=contribute
(thus leaving out the beginning of the absolute path) I get an error about a missing parameter but not a 404.

Both domains are hosted on one account, but the web directory for mydomain.org is a symlink to the web directory for myprincipaldomain.org, so it runs off the same Drupal codebase.

The url fed to Paypal does reflect the full absolute path to the ipn.php file, but plugging that in after the web domain mydomain.org doesn't make a lot of sense.

What I don't understand is that this used to work a couple of years ago, and I'm not sure what has changed. Help!