An IPN transaction failed verification for this order.

I'm having the same issue. My watchdog table show these two errors when I hit the return the merchant link from paypal (Sandbox). I'm using the "PayPal - pay without sharing your financial information." option when checking out. I'm also having a problem where the invoice is being sent out with a $0.00 total if they are linked. URL is more info. http://www.ubercart.org/forum/support/1004/order_confirmation_email.

type: uc_paypal
message: Receiving IPN at URL for order !order_id.
variables: a:1:{s:9:"!order_id";s:1:"6";}

type: uc_paypal
message: IPN transaction failed verification.
variables: a:0:{}

I get this as well and can not nail down as to what it would be.

I get the error both in the Sandbox and with the Live transaction.

We seem to be failing this test to result in a failed transaction...

 if (strcmp ($res, 'VERIFIED') == 0) {

It's line 611 of the uc.payment.module

Failing this test would send us to here...

elseif (strcmp($res, 'INVALID') == 0) {
      watchdog('uc_paypal', 'IPN transaction failed verification.', array(), WATCHDOG_ERROR);
      uc_order_comment_save($order_id, 0, t('An IPN transaction failed verification for this order.'), 'admin');
    }

Starting at line 677 of the uc.payment.module

ok... found the fix for this

change this

  foreach ($_POST as $key => $value) {
    $value = drupal_urlencode(stripslashes($value));
    $req .= '&'. $key .'='. $value;
  }

to this

  foreach ($_POST as $key => $value) {
    $value = urlencode(stripslashes($value));
    $req .= '&'. $key .'='. $value;
  }

and it works.

Committed.

Oh man! My first commit... on a project like Ubercart too! What an honor. :D

: D